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University of Delaware
1.
Hu, Xiaocao.
Synthesis and characterization of magnetically hard Fe-Pt alloy nanoparticles and nano-islands.
Degree: PhD, University of Delaware, Department of Materials Science and Engineering, 2016, University of Delaware
URL: http://udspace.udel.edu/handle/19716/17738 
► In this dissertation, we explored the fabrication of FePt nanoparticles and nano-islands with the face-centered tetragonal (fct, L10) phase prepared by both chemical synthesis routes…
(more)
▼ In this dissertation, we explored the fabrication of FePt nanoparticles and nano-islands with the face-centered tetragonal (fct, L10) phase prepared by both chemical synthesis routes and physical vapor deposition. Microstructure and magnetic properties characterizations were used to gain a fundamental understanding of the nano-structure formation and atomic ordering behavior and determine the possible applications in the next generation ultra-high density magnetic storage media.
FePt nanoparticles prepared by thermal decomposition of iron pentacarbonyl [Fe(CO)5] have been widely investigated and by tuning the processing procedure monodispersed FePt nanoparticles with good assembly can be obtained. The as-made FePt nanoparticles are usually in the magnetically soft face-centered cubic (fcc) phase. To transformation to the fct phase, post-annealing at above 600°C is needed which, however, introduces undesirable agglomeration and sintering. To address this problem, we used three different fabrication processes which are discussed below.
In the first fabrication experiment, the FePt nanoparticles were fabricated by a novel environmental friendly method involving crystalline saline complex hexaaquairon (II) hexachloroplatinate ([Fe(H2O)6]PtCl 6) with a special layered structure. Then the precursor was ball milled with NaCl and annealed at temperatures above 400°C under a reducing atmosphere of forming gas (95% Ar and 5% H2) FePt nanoparticles were obtained after washing away NaCl with deionized water. This method avoids the use of the very poisonous Fe(CO)5 and other organic solvents such as oleylamine and oleic acid. Instead, environmentally friendly NaCl and water were used. The size of FePt nanoparticles was controlled by varying the proportion of precursor and NaCl (from 10mg/20g to 50mg/20g). Particles with size in the range of 6.2–13.2 nm were obtained. All the nanoparticles annealed above 400°C are in the highly ordered fct phase with a coercivity range of 4.7 kOe to 10.7 kOe. Compared with reported high annealing temperatures above 600°C, this fabrication process led to a significantly decreased temperature to achieve the L10 phase FePt by 200°C. A qualitative model was set up to explain the surprising low L10 phase achievement temperature and the influence of annealing temperature on the microstructure and magnetic properties was investigated.
Although FePt nanoparticles with high coercivity and small size were successfully obtained by the first fabrication method, agglomeration happened during the washing procedure due to the large inter-particle magnetostatic force caused by their high magnetization. To avoid this agglomeration, exfoliated graphene was introduced in the second preparation method to keep the nanoparticles separated. Different from the traditional solvent-phase reaction to disperse FePt nanoparticles onto the exfoliated graphene, a novel solid-phase reaction was used in this dissertation involving the layered precursor [Fe(H2 O)6]PtCl6 molecule. The [Fe(H2O) 6]PtCl6 water solution was…
Advisors/Committee Members: Hadjipanayis, George C..
Subjects/Keywords: Iron alloys.; Platinum alloys.; Magnetic alloys.; Nanoparticles.
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APA (6th Edition):
Hu, X. (2016). Synthesis and characterization of magnetically hard Fe-Pt alloy nanoparticles and nano-islands. (Doctoral Dissertation). University of Delaware. Retrieved from http://udspace.udel.edu/handle/19716/17738
Chicago Manual of Style (16th Edition):
Hu, Xiaocao. “Synthesis and characterization of magnetically hard Fe-Pt alloy nanoparticles and nano-islands.” 2016. Doctoral Dissertation, University of Delaware. Accessed April 11, 2021.
http://udspace.udel.edu/handle/19716/17738.
MLA Handbook (7th Edition):
Hu, Xiaocao. “Synthesis and characterization of magnetically hard Fe-Pt alloy nanoparticles and nano-islands.” 2016. Web. 11 Apr 2021.
Vancouver:
Hu X. Synthesis and characterization of magnetically hard Fe-Pt alloy nanoparticles and nano-islands. [Internet] [Doctoral dissertation]. University of Delaware; 2016. [cited 2021 Apr 11].
Available from: http://udspace.udel.edu/handle/19716/17738.
Council of Science Editors:
Hu X. Synthesis and characterization of magnetically hard Fe-Pt alloy nanoparticles and nano-islands. [Doctoral Dissertation]. University of Delaware; 2016. Available from: http://udspace.udel.edu/handle/19716/17738
2.
Du, Ningning.
Multi-scale Modeling of Deformation and Failure Mechanisms
of Al Alloys at Elevated Temperature.
Degree: PhD, Division of Engineering. Mechanics of
Solids, 2009, Brown University
URL: https://repository.library.brown.edu/studio/item/bdr:193/
► When deformed at elevated temperature and slow strain rates, some Al alloys exhibits superplasticity, the ability to sustain very large tensile elongations (sometimes over 1000%)…
(more)
▼ When deformed at elevated temperature and slow strain
rates, some Al
alloys exhibits superplasticity, the ability to
sustain very large tensile elongations (sometimes over 1000%) prior
to failure in a generally isotropic manner. This property has been
exploited in industrial manufacturing processes such as
superplastic forming and quick plastic forming. This dissertation
investigated some aspects that are related to the deformation and
failure of Al
alloys at elevated temperature with numerical
simulations of multiple time and length scales. First, a finite
element method rigorously accounts for three main deformation
mechanisms in superplasticity, namely the grain interior
plasticity, grain boundary diffusion and grain boundary sliding is
given. The method was used to predict the constitutive response and
contribution of each mechanism to the total plastic strain based on
microstructures of an assembly of grains. The microstructure finite
element model is also used to conduct a systematic study of the
mechanisms of void growth in polycrystalline Al AA5083 during
elevated temperature straining. Second, to further understand the
nature of grain boundary sliding, molecular dynamics simulations
are used to investigate the effect of vacancies, Si and Mg
impurities in the Al grain boundaries on grain boundary sliding.
Finally, a multi-scale approach that links the microstructure based
finite element model to the continuum scale finite element
simulations of elevated temperature forming of Al
alloys is
proposed and used to study the bulge forming process. The work of
this dissertation should be useful toward making reliable
quantitive predictions of Al and similar superplastic
alloys, and
ultimately modifying and designing engineered superplastic
materials that is suitable for various purposes.
Advisors/Committee Members: Bower, Allan (director), Gao, Huajian (reader), Chason, Eric (reader).
Subjects/Keywords: Al alloys
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APA (6th Edition):
Du, N. (2009). Multi-scale Modeling of Deformation and Failure Mechanisms
of Al Alloys at Elevated Temperature. (Doctoral Dissertation). Brown University. Retrieved from https://repository.library.brown.edu/studio/item/bdr:193/
Chicago Manual of Style (16th Edition):
Du, Ningning. “Multi-scale Modeling of Deformation and Failure Mechanisms
of Al Alloys at Elevated Temperature.” 2009. Doctoral Dissertation, Brown University. Accessed April 11, 2021.
https://repository.library.brown.edu/studio/item/bdr:193/.
MLA Handbook (7th Edition):
Du, Ningning. “Multi-scale Modeling of Deformation and Failure Mechanisms
of Al Alloys at Elevated Temperature.” 2009. Web. 11 Apr 2021.
Vancouver:
Du N. Multi-scale Modeling of Deformation and Failure Mechanisms
of Al Alloys at Elevated Temperature. [Internet] [Doctoral dissertation]. Brown University; 2009. [cited 2021 Apr 11].
Available from: https://repository.library.brown.edu/studio/item/bdr:193/.
Council of Science Editors:
Du N. Multi-scale Modeling of Deformation and Failure Mechanisms
of Al Alloys at Elevated Temperature. [Doctoral Dissertation]. Brown University; 2009. Available from: https://repository.library.brown.edu/studio/item/bdr:193/
Oregon State University
3.
Biskey, John Wesley.
The development of Fe-Cr-C based alloys for high wear and high impact applications.
Degree: MS, Mechanical and Metallurgical Engineering, 1975, Oregon State University
URL: http://hdl.handle.net/1957/44395
► The structure, hardness, and impact strength of high chromium cast irons was investigated. From the Fe- Cr- C phase diagram, a composition with 74.8 wt%…
(more)
▼ The structure, hardness, and impact strength of high chromium
cast irons was investigated. From the Fe- Cr- C phase diagram,
a composition with 74.8 wt% Fe, 21.5 wt% Cr, and 3.7 wt% was
selected along the austenite-M₇C₃ eutectic trough. This composition
was bracketed by others with slightly different amounts of iron,
chromium, and carbon. These basic
alloys were then modified
with additions of manganese, nickel, titanium, and silicon.
Hardness measurements were made on small arc melted
buttons and on cast impact specimens. The hardness of these
alloys
varied from Rc 45 (BHN 425) to Rc 65 (BHN 750).
The impact specimens were round pins for a modified Izod
test. Most
alloys had impact strengths from 2 to 3 ft-lb. However,
a slightly hypoeutectic alloy had an impact strength of 7 ft-lb at
room temperature and 5 ft-lb at -40°F (-40°C). This was obtained with an alloy of 74 wt% Fe, 18.8 wt% Cr, 3. 7 wt% C, 2 wt% Mn,
2 wt% Ni, and 0.5 wt% Si.
Based on these limited tests, it was concluded that it should
be possible to develop a moderately tough Fe-Cr-C based cast iron.
Alloys with this toughness, combined with the high hardness,
should find applications in the mining and ore handling industry.
Advisors/Committee Members: Paasche, Olaf G. (advisor).
Subjects/Keywords: Alloys
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APA (6th Edition):
Biskey, J. W. (1975). The development of Fe-Cr-C based alloys for high wear and high impact applications. (Masters Thesis). Oregon State University. Retrieved from http://hdl.handle.net/1957/44395
Chicago Manual of Style (16th Edition):
Biskey, John Wesley. “The development of Fe-Cr-C based alloys for high wear and high impact applications.” 1975. Masters Thesis, Oregon State University. Accessed April 11, 2021.
http://hdl.handle.net/1957/44395.
MLA Handbook (7th Edition):
Biskey, John Wesley. “The development of Fe-Cr-C based alloys for high wear and high impact applications.” 1975. Web. 11 Apr 2021.
Vancouver:
Biskey JW. The development of Fe-Cr-C based alloys for high wear and high impact applications. [Internet] [Masters thesis]. Oregon State University; 1975. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/1957/44395.
Council of Science Editors:
Biskey JW. The development of Fe-Cr-C based alloys for high wear and high impact applications. [Masters Thesis]. Oregon State University; 1975. Available from: http://hdl.handle.net/1957/44395
Nelson Mandela Metropolitan University
4.
Oyekunle, Funsho Adekunle.
Optical diamond turning of rapidly solidified aluminium alloy grade - 431.
Degree: 2020, Nelson Mandela Metropolitan University
URL: http://hdl.handle.net/10948/46860
► The high demand for ultraprecision machining systems is increasing day by day. The technology leads to increased productivity and quality manufactured products, with an excellent…
(more)
▼ The high demand for ultraprecision machining systems is increasing day by day. The technology leads to increased productivity and quality manufactured products, with an excellent surface finish. Therefore, these products are in demand in many industrial fields such as space, national defence, the medical industry and other high-tech industries. Single point diamond turning (SPDT) is the core technology of ultraprecision machining, which makes use of single-point crystalline diamond as a cutting tool. This technique is used for machining an extensive selection of complex optical surfaces and other engineering products with a quality surface finish. SPDT can achieve dimensional tolerances in order of 0.01um and surface roughness in order of 1nm. SPDT is not restricted, but mostly applicable, to non-ferrous alloys; due to their reflective properties and microstructure that discourages tool wear. The focus of this study is the development of predictive optimisation models, used to analyse the influence of machining parameters (speed, feed, and depth of cut) on surface roughness. Moreover, the study aims to obtain the optimal machining parameters that would lead to minimum surface roughness during the diamond turning of Rapidly Solidified Aluminium (RSA) 431. In this study, Precitech Nanoform 250 Ultra grind machine was used to perform two experiments on RSA 431. The first machining process, experiment 1, was carried out using pressurized kerosene mist; while experiment 2 was carried out with water as the cutting fluid. In each experiment, machine parameters were varied at intervals and the surface roughness of the workpiece was measured at each variation. The measurements were taken through a contact method using Taylor Hobson PGI Dimension XL surface Profilometer. Acoustic emission (AE) was employed as a precision sensing technique – to optimize the machining quality process and provide indications of the expected surface roughness. The results obtained revealed that better surface roughness can be generated when RSA 431 is diamond-turned using water as a cutting fluid, rather than kerosene mist. Predictive models for surface roughness were developed for each experiment, using response surface methodology (RSM) and artificial neural networks (ANN). Moreover, RSM was used for optimisation. Time domain features acquired from AE signals, together with the three cutting parameters, were used as input parameters in the ANN design. The results of the predictive models show a close relationship between the predicted values and the experimental values for surface roughness. The developed models have been compared in terms of accuracy and cost of computation - using the mean absolute percentage error (MAPE).
Subjects/Keywords: Aluminum alloys
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APA (6th Edition):
Oyekunle, F. A. (2020). Optical diamond turning of rapidly solidified aluminium alloy grade - 431. (Thesis). Nelson Mandela Metropolitan University. Retrieved from http://hdl.handle.net/10948/46860
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Oyekunle, Funsho Adekunle. “Optical diamond turning of rapidly solidified aluminium alloy grade - 431.” 2020. Thesis, Nelson Mandela Metropolitan University. Accessed April 11, 2021.
http://hdl.handle.net/10948/46860.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Oyekunle, Funsho Adekunle. “Optical diamond turning of rapidly solidified aluminium alloy grade - 431.” 2020. Web. 11 Apr 2021.
Vancouver:
Oyekunle FA. Optical diamond turning of rapidly solidified aluminium alloy grade - 431. [Internet] [Thesis]. Nelson Mandela Metropolitan University; 2020. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/10948/46860.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Oyekunle FA. Optical diamond turning of rapidly solidified aluminium alloy grade - 431. [Thesis]. Nelson Mandela Metropolitan University; 2020. Available from: http://hdl.handle.net/10948/46860
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Michigan State University
5.
Weston, Keith A.
Construction of the equilibrium diagram for an alloy.
Degree: B.S., 1921, Michigan State University
URL: http://etd.lib.msu.edu/islandora/object/etd:48969
Subjects/Keywords: Alloys
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APA (6th Edition):
Weston, K. A. (1921). Construction of the equilibrium diagram for an alloy. (Thesis). Michigan State University. Retrieved from http://etd.lib.msu.edu/islandora/object/etd:48969
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Weston, Keith A. “Construction of the equilibrium diagram for an alloy.” 1921. Thesis, Michigan State University. Accessed April 11, 2021.
http://etd.lib.msu.edu/islandora/object/etd:48969.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Weston, Keith A. “Construction of the equilibrium diagram for an alloy.” 1921. Web. 11 Apr 2021.
Vancouver:
Weston KA. Construction of the equilibrium diagram for an alloy. [Internet] [Thesis]. Michigan State University; 1921. [cited 2021 Apr 11].
Available from: http://etd.lib.msu.edu/islandora/object/etd:48969.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Weston KA. Construction of the equilibrium diagram for an alloy. [Thesis]. Michigan State University; 1921. Available from: http://etd.lib.msu.edu/islandora/object/etd:48969
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Michigan State University
7.
Burnett, James Robert.
Short-time heat treating characteristics of a binary copper-beryllium alloy.
Degree: MS, 1949, Michigan State University
URL: http://etd.lib.msu.edu/islandora/object/etd:9874
Subjects/Keywords: Alloys
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APA (6th Edition):
Burnett, J. R. (1949). Short-time heat treating characteristics of a binary copper-beryllium alloy. (Masters Thesis). Michigan State University. Retrieved from http://etd.lib.msu.edu/islandora/object/etd:9874
Chicago Manual of Style (16th Edition):
Burnett, James Robert. “Short-time heat treating characteristics of a binary copper-beryllium alloy.” 1949. Masters Thesis, Michigan State University. Accessed April 11, 2021.
http://etd.lib.msu.edu/islandora/object/etd:9874.
MLA Handbook (7th Edition):
Burnett, James Robert. “Short-time heat treating characteristics of a binary copper-beryllium alloy.” 1949. Web. 11 Apr 2021.
Vancouver:
Burnett JR. Short-time heat treating characteristics of a binary copper-beryllium alloy. [Internet] [Masters thesis]. Michigan State University; 1949. [cited 2021 Apr 11].
Available from: http://etd.lib.msu.edu/islandora/object/etd:9874.
Council of Science Editors:
Burnett JR. Short-time heat treating characteristics of a binary copper-beryllium alloy. [Masters Thesis]. Michigan State University; 1949. Available from: http://etd.lib.msu.edu/islandora/object/etd:9874
University of Limerick
8.
Richardson, David.
Nanotubes prepared by electroless deposition: investigation of the nanostructure formation mechanism and characterisation of physical properties.
Degree: 2015, University of Limerick
URL: http://hdl.handle.net/10344/8104
► peer-reviewed
In this research, we investigate electrolessly deposited nanotubes due to their unique associated magnetic and catalytic properties. The main challenge associated with electroless deposition…
(more)
▼ peer-reviewed
In this research, we investigate electrolessly deposited nanotubes due to their unique associated magnetic and catalytic properties. The main challenge associated with electroless deposition is the formation of a nanotube structure with a uniform wall thickness. In this study, we investigate the electroless deposition process of nanotubes within a polycarbonate membrane. By identifying the conditions required to ensure a kinetically controlled deposition process, we achieve the formation of continuous nanotubes with a uniform wall thickness.
Electrolessly deposited alloys containing Ni, Fe and Co are magnetic and have many potential applications in future technologies. In this work, we investigate the magnetic properties of a series of alloys including Ni-B, Ni-Fe-B, Co-B and Ni-Cu-B nanotube structures. We establish the relationships between the magnetic properties of the nanostructure and their structure and compositional parameters. We also characterise the magnetic reversal mechanisms associated with the nanotube structure, which depend on the alloy used. We achieve a maximum specific magnetisation of 84.3 J T-1 kg-1 and a minimum coercivity of 0.003 T.
Alloyed deposits containing B can be used to catalyse hydrogen release from an alkaline NaBH4 solution. In this study, a variety of nanostructured alloys, including Ni-B, Co-B, NiCu-B, NiFe-B and NiCo-B and CoNiFe-B are investigated as catalysts for hydrogen generation. We show that nanostructured catalysts have larger hydrogen generation than metallic films with a maximum hydrogen generation rate of 10,800 ml min-1 g-1.
Advisors/Committee Members: Rhen, Fernando M.F., IRC.
Subjects/Keywords: nanotubes; alloys
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APA (6th Edition):
Richardson, D. (2015). Nanotubes prepared by electroless deposition: investigation of the nanostructure formation mechanism and characterisation of physical properties. (Thesis). University of Limerick. Retrieved from http://hdl.handle.net/10344/8104
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Richardson, David. “Nanotubes prepared by electroless deposition: investigation of the nanostructure formation mechanism and characterisation of physical properties.” 2015. Thesis, University of Limerick. Accessed April 11, 2021.
http://hdl.handle.net/10344/8104.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Richardson, David. “Nanotubes prepared by electroless deposition: investigation of the nanostructure formation mechanism and characterisation of physical properties.” 2015. Web. 11 Apr 2021.
Vancouver:
Richardson D. Nanotubes prepared by electroless deposition: investigation of the nanostructure formation mechanism and characterisation of physical properties. [Internet] [Thesis]. University of Limerick; 2015. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/10344/8104.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Richardson D. Nanotubes prepared by electroless deposition: investigation of the nanostructure formation mechanism and characterisation of physical properties. [Thesis]. University of Limerick; 2015. Available from: http://hdl.handle.net/10344/8104
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Indian Institute of Science
9.
Shrikant, Joshi Sameehan.
Development Of Cast Magnesium Alloys With Improved Strength.
Degree: MSc Engg, Faculty of Engineering, 2014, Indian Institute of Science
URL: http://etd.iisc.ac.in/handle/2005/2311
► Aim of the present work was to explore the possibility of improving strength of cast Mg by alloying additions, viz., Si and Zn+Al. All the…
(more)
▼ Aim of the present work was to explore the possibility of improving strength of cast Mg by alloying additions, viz., Si and Zn+Al. All the
alloys were produced by squeeze casting technique using squeeze pressure of 12MPa and their microstructure, tensile and corrosion properties were studied.
Mg-Si system was chosen because the intermetallic compound Mg2Si possesses many desirable properties, such as, low density, high hardness, high melting point. Hence, there is scope for improving the strength of Mg by dispersion of primary Mg2Si particles. Addition of Si to Mg resulted in the formation of �-Mg, particles of primary Mg2Si and eutectic as microstructural constituents. The morphology of primary Mg2Si changed from polyhedral shaped particles to dendrites as Si content was increased from 3.57 to 5.5 wt%. Volume fraction of primary Mg2Si increased with increase in Si content. Particle size of primary Mg2Si also increased with increase in silicon content but at the same time it was found to be dependent on melt temperature, i.e., a lower particle size was obtained at higher melt temperatures. Addition of Al and Sr was made to Mg-2Si alloy in order to further increase the strength by solid solution strengthening and refinement/modification of primary Mg2Si particles/eutectic. Addition of 1.2 wt% Al to Mg-2Si alloy resulted in irregular type of morphology of Mg2Si particles and increased particle size. Addition of 0.2 wt% SrtoMg-2Si-1.2Al alloy resulted in slight refinement of primary Mg2Si particles and modification of eutectic. Addition of 0.4 wt% Sr resulted in both refinement and restoration of morphology of Mg2Si particles from irregular to polyhedral shape. This was accompanied by destruction of eutectic, and rods containing Mg, Si, Al and Sr were observed.
The addition of 1.33 wt%Si to Mg resulted in improvement in 0.2%PS by about 80 MPa,UTS by about 40MPa and these values did not change much till the addition of 3.57 wt% Si. A drop in the strength values was observed at Si content of 5.5 wt%,where transition in morphology of primary Mg2Si occurred from polyhedral to dendrite. Addition of Si resulted in reduction in % elongation by about 2%. The addition of Al and Sr did not change the tensile properties of binary Mg-2Si alloy much. It was concluded that the volume fraction and size of primary Mg2Siparticles obtained with Si addition up to 3.57 wt% did not contribute much to strength and the strengthening mainly came from the eutectic present in the matrix. As Si content was increased to 5.5 wt% in order to increase the volume fraction of primary Mg2Si particles, the morphology of Mg2Si changed to dendritic type resulting in reduction in strength. Thus, the maximum increase in strength is achieved at near eutectic composition,i.e.,intheMg-1.33Sialloy,andfurtherincreaseinstrengthdoesnotseem to be feasible with this alloy system. The ductility of all the Mg-Si based
alloys was also low, i.e, 0.5% elongation to fracture or less. Regarding the corrosion behaviour, the addition of Si to Mg deteriorated the corrosion…
Advisors/Committee Members: Kumar, Subodh (advisor).
Subjects/Keywords: Magnesium Alloys; Magnesium-Silicon Alloys; Magnesium-Zinc Alloys; Cast Magnesium Alloys; Magnesium Alloys - Microstructure; Magnesium Alloys - Tensile Properties; Magnesium Alloys - Corrosion; Mg Alloys; Mg-Si Alloys; Mg-Zn Alloys; Metallurgy
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APA (6th Edition):
Shrikant, J. S. (2014). Development Of Cast Magnesium Alloys With Improved Strength. (Masters Thesis). Indian Institute of Science. Retrieved from http://etd.iisc.ac.in/handle/2005/2311
Chicago Manual of Style (16th Edition):
Shrikant, Joshi Sameehan. “Development Of Cast Magnesium Alloys With Improved Strength.” 2014. Masters Thesis, Indian Institute of Science. Accessed April 11, 2021.
http://etd.iisc.ac.in/handle/2005/2311.
MLA Handbook (7th Edition):
Shrikant, Joshi Sameehan. “Development Of Cast Magnesium Alloys With Improved Strength.” 2014. Web. 11 Apr 2021.
Vancouver:
Shrikant JS. Development Of Cast Magnesium Alloys With Improved Strength. [Internet] [Masters thesis]. Indian Institute of Science; 2014. [cited 2021 Apr 11].
Available from: http://etd.iisc.ac.in/handle/2005/2311.
Council of Science Editors:
Shrikant JS. Development Of Cast Magnesium Alloys With Improved Strength. [Masters Thesis]. Indian Institute of Science; 2014. Available from: http://etd.iisc.ac.in/handle/2005/2311
Nelson Mandela Metropolitan University
10.
Akinlabi, Esther Titilayo.
Characterisation of dissimilar friction stir welds between 5754 Aluminium alloy and C11000 copper.
Degree: Faculty of Engineering, the Built Environment and Information Technology, 2010, Nelson Mandela Metropolitan University
URL: http://hdl.handle.net/10948/1536
► Friction Stir Welding (FSW) is a solid state welding process invented and patented by The Welding Institute (TWI) in 1991, for joining ferrous and non-ferrous…
(more)
▼ Friction Stir Welding (FSW) is a solid state welding process invented and patented by The Welding Institute (TWI) in 1991, for joining ferrous and non-ferrous materials1. The FSW of Aluminium and its alloys has been commercialised; and recent interest is focused on joining dissimilar materials. However, in order to commercialise the process, research studies are required to characterise and establish process windows. This research work through material characterisation of the welded joints establishes a process window for the Friction Stir welding of 5754 Aluminium Alloy and C11000 Copper. Furthermore, preliminary studies83,85 on the FSW of aluminium and copper have revealed the presence of intermetallic compounds which are detrimental to the weld qualities. This research work is also aimed at establishing process parameters that will result in limited or no intermetallic formation in the weld. The joint integrity of the resulting welds will also be correlated with the input process parameters. Based on the preliminary investigations conducted, a final weld matrix consisting of twenty seven welds was produced by varying the rotational speed between 600 and 1200 rpm, and the feed rate between 50 and 300 mm/min using three different shoulder diameter tools – 15, 18 and 25 mm to compare the heat input into the welds and to achieve the best results. The welds were characterised through microstructural evaluation, tensile testing, microhardness profiling, X-Ray Diffraction analysis, electrical resistivity and statistical analysis – in order to establish the interrelationship between the process parameters and the weld qualities. viii Microstructural evaluation of the weld samples revealed that the interfacial regions are characterised by mixture layers of aluminium and copper; while 33 percent of the tensile samples are within the acceptable range (> 75 percent joint efficiency). High Vickers microhardness values were measured at the joint interfaces, which corresponded with the intermetallic compounds. The Energy Dispersive Spectroscopy analysis revealed the presence of thin layers of intermetallics in nanoscale at the interfacial regions. The diffractograms of the X-Ray Diffraction analysis showed small peaks for intermetallics in some of the welds. Low electrical resistivities were measured at the joint interfaces. The statistical analysis showed that the downward vertical force, (Fz) can significantly influence the resulting weld qualities. An overall summary of the analysis of the weld qualities - with respect to the shoulder diameter tools employed showed that the 18 mm shoulder diameter tool is most appropriate among the three shoulder diameters considered, and a process window of medium spindle speed of 950 rpm and low-to-medium feed rate between 50 and 150 mm/min is established for FSW of Aluminium and Copper. Welds produced at 1200 rpm and 300 mm/min with low heat input did not have intermetallics formed at the joint interface.
Subjects/Keywords: Friction stir welding; Aluminum alloys; Copper alloys
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APA (6th Edition):
Akinlabi, E. T. (2010). Characterisation of dissimilar friction stir welds between 5754 Aluminium alloy and C11000 copper. (Thesis). Nelson Mandela Metropolitan University. Retrieved from http://hdl.handle.net/10948/1536
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Akinlabi, Esther Titilayo. “Characterisation of dissimilar friction stir welds between 5754 Aluminium alloy and C11000 copper.” 2010. Thesis, Nelson Mandela Metropolitan University. Accessed April 11, 2021.
http://hdl.handle.net/10948/1536.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Akinlabi, Esther Titilayo. “Characterisation of dissimilar friction stir welds between 5754 Aluminium alloy and C11000 copper.” 2010. Web. 11 Apr 2021.
Vancouver:
Akinlabi ET. Characterisation of dissimilar friction stir welds between 5754 Aluminium alloy and C11000 copper. [Internet] [Thesis]. Nelson Mandela Metropolitan University; 2010. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/10948/1536.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Akinlabi ET. Characterisation of dissimilar friction stir welds between 5754 Aluminium alloy and C11000 copper. [Thesis]. Nelson Mandela Metropolitan University; 2010. Available from: http://hdl.handle.net/10948/1536
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Nelson Mandela Metropolitan University
11.
Nyembe, Hlanganani Siphelele.
Corrosion resistance of nanocrystalline titanium zirconium nitride layers deposited on ZIRLO.
Degree: 2018, Nelson Mandela Metropolitan University
URL: http://hdl.handle.net/10948/34744
► Zirconium (Zr) alloys are used as nuclear fuel cladding in water-cooled nuclear reactors. Being in contact with steam, the Zr-alloy is oxidised and it absorbs…
(more)
▼ Zirconium (Zr) alloys are used as nuclear fuel cladding in water-cooled nuclear reactors. Being in contact with steam, the Zr-alloy is oxidised and it absorbs hydrogen. The hydrogen pickup in Zr-alloys induces embrittlement of the tubes due to hydride formation. In this study, effectiveness of corrosion resistant nanocrystalline titanium zirconium nitride (nc-TiZrN) coatings on the surface of a Zr-alloy for the reduction of corrosion and hydrogen pickup is investigated. The nc-TiZrN layers were deposited onto the surface of ZIRLO® using the cathodic arc vapour deposition (CAVD) technique. The influence of nc-TiZrN coatings on the corrosion performance of ZIRLO® was investigated under the following conditions: (a) In an oxygen atmosphere at various temperatures from 400 to 900 ℃ for 30 minutes, (b) for various exposure times from 6 – 24 hours with the temperature kept constant at 500 ℃ in a tube furnace, and (c) in pure steam for 30 days at 360 ℃ and 18.7 MPa in an autoclave. The corrosion properties of the nc-TiZrN coated ZIRLO were compared to uncoated ZIRLO for all experiments. Following corrosion testing, the TiZrN coatings and oxide layers were investigated by scanning and transmission electron microscopy and energy dispersive X-ray spectroscopy. The TiZrN coating had a thickness of ~3.8 μm with a small number of Ti-rich and Nb-rich inclusions. The coating exhibited a single phase solid solution of Ti0.42Zr0.58N with a NaCl-type crystal structure and columnar nanocrystals. These columnar nanocrystals showed a strong {111} preferred orientation and the {111} planes of the TiZrN crystals are oriented parallel to the (001) planes of α-ZIRLO grains with <001> direction perpendicular to the coating/ZIRLO interface. The corrosion testing at various temperatures from 400 to 900 ℃ for 30 minutes showed that the TiZrN coating oxidises slowly and retained its microstructure, composition and crystallinity up to 600 ℃. At higher temperatures above 600 ℃, the TiZrN layer completely oxidised to a non-protective TiZr-oxide layer and resulted in rapid corrosion of the underlying ZIRLO substrate. The rapid corrosion was not observed in the uncoated ZIRLO sample for all temperatures. The results of samples subjected to annealing treatment at 500 ℃ in an oxygen atmosphere at various times up to 24 hours revealed that the TiZrN layer oxidises faster than ZIRLO. This was confirmed by sub-cubic and sub-parabolic oxide growth kinetics observed in the uncoated ZIRLO which are slower than the parabolic kinetics of TiZrN coated samples. In all coated samples, the spallation was observed near the edges of the samples. The spallation was caused by rapid corrosion of the underlying ZIRLO substrate which resulted from the penetration of oxygen ions between the TiZrN coating and ZIRLO substrate along the edges of the samples. In pure steam for 30 days at 360 ℃, a complete loss of the TiZrN layer occurred but the results show that the coating might have delayed the corrosion of ZIRLO. In summary, corrosion resistance of nc-TiZrN coated ZIRLO…
Subjects/Keywords: Zirconium alloys; Titanium alloys; Nanocrystals; Nanotechnology
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APA (6th Edition):
Nyembe, H. S. (2018). Corrosion resistance of nanocrystalline titanium zirconium nitride layers deposited on ZIRLO. (Thesis). Nelson Mandela Metropolitan University. Retrieved from http://hdl.handle.net/10948/34744
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Nyembe, Hlanganani Siphelele. “Corrosion resistance of nanocrystalline titanium zirconium nitride layers deposited on ZIRLO.” 2018. Thesis, Nelson Mandela Metropolitan University. Accessed April 11, 2021.
http://hdl.handle.net/10948/34744.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Nyembe, Hlanganani Siphelele. “Corrosion resistance of nanocrystalline titanium zirconium nitride layers deposited on ZIRLO.” 2018. Web. 11 Apr 2021.
Vancouver:
Nyembe HS. Corrosion resistance of nanocrystalline titanium zirconium nitride layers deposited on ZIRLO. [Internet] [Thesis]. Nelson Mandela Metropolitan University; 2018. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/10948/34744.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Nyembe HS. Corrosion resistance of nanocrystalline titanium zirconium nitride layers deposited on ZIRLO. [Thesis]. Nelson Mandela Metropolitan University; 2018. Available from: http://hdl.handle.net/10948/34744
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Illinois – Urbana-Champaign
12.
Stephenson, Edward Beattie.
Magnetic Properties of Heusler Alloys.
Degree: PhD, University of Illinois at Urbana-Champaign, 1910, University of Illinois – Urbana-Champaign
URL: http://hdl.handle.net/2142/16433
Subjects/Keywords: Heusler alloys; Alloys
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APA (6th Edition):
Stephenson, E. B. (1910). Magnetic Properties of Heusler Alloys. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/16433
Chicago Manual of Style (16th Edition):
Stephenson, Edward Beattie. “Magnetic Properties of Heusler Alloys.” 1910. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed April 11, 2021.
http://hdl.handle.net/2142/16433.
MLA Handbook (7th Edition):
Stephenson, Edward Beattie. “Magnetic Properties of Heusler Alloys.” 1910. Web. 11 Apr 2021.
Vancouver:
Stephenson EB. Magnetic Properties of Heusler Alloys. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 1910. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/2142/16433.
Council of Science Editors:
Stephenson EB. Magnetic Properties of Heusler Alloys. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 1910. Available from: http://hdl.handle.net/2142/16433
University of Illinois – Urbana-Champaign
13.
Wu, Yan.
Advanced experimental characterization of deformation mechanisms and temperature changes on novel alloys systems.
Degree: PhD, Mechanical Engineering, 2019, University of Illinois – Urbana-Champaign
URL: http://hdl.handle.net/2142/104757
► The human civilization continues to benefit from novel alloys systems ascribed to their unprecedented functionalities. Among many, shape memory alloys (SMAs) and high entropy alloys…
(more)
▼ The human civilization continues to benefit from novel
alloys systems ascribed to their unprecedented functionalities. Among many, shape memory
alloys (SMAs) and high entropy
alloys (HEAs) are presently of great research interest in material science and engineering community. Unlike conventional
alloys, the former exhibits astonishing recoverability from excessive deformation and the latter possesses exceptional strength and ductility extending to cryogenic temperatures. This work investigates the high temperature response and elastocaloric effect of SMAs and strain hardening behavior of HEAs using advanced experimental techniques, i.e. digital image correlation (DIC), optical microscopy, electron microscopy, etc.
In the first portion of this dissertation, the mechanical responses of the NiTiHf high temperature SMAs are investigated. This class of materials represent a significant advancement in extending the functionality of binary NiTi to elevated temperatures above 100 °C. Despite this potential, the previous results in the literature point to a disappointingly low transformation strains with addition of Hf. On the other hand, based on theoretical analysis using the lattice constants, the transformation strains should increase substantially with increase in Hf content. The present study addresses this discrepancy. Using DIC, the transformation strain is established with very careful strain measurements at small scales in both isobaric and isothermal experiments. Because of the heterogeneity of strain distributions, the results depend on the sub-region considered. By scrutinizing the alloy systems with Hf content in the range from 12.5 to 25 at.%, we show that the experimental transformation strains in NiTiHf indeed increase with increasing Hf to unprecedented strain levels near 20%.
In the second part of this dissertation, the elastocaloric (EC) effect of SMA is examined. The EC effect refers to the rapid cooling in SMAs during reverse transformation from martensite to austenite under adiabatic conditions. We present a very comprehensive study of the EC response far extending the existing literature by studying the effect of loading states (tension and compression), long-term cycling, strain localization, and deformation temperatures in several alloy systems including CuZnAl, NiTi, NiTiCu, Ni2FeGa and NiTiHf13.3. We found a substantial temperature change of 14.2 °C in CuZnAl, 18.2 °C in NiTi, 15.2 °C in NiTiCu, 13.5 °C in Ni2FeGa, and 6.95 °C in NiTiHf13.3 upon reverse transformation depending on the entropy change (as high as 60 J/kg K), the stress hysteresis, the inhomogeneity of the transformation and the number of superelastic cycles. A gradual deterioration of the EC effect in tension develops, while in compression the EC effect can be sustained much longer (in excess of 104 cycles). The Ni2FeGa SMAs possess an operational EC temperature window of nearly 200 °C, which is the widest among the chosen SMAs. With over one hundred experiments reported, the current study represents an authoritative summary of the…
Advisors/Committee Members: Sehitoglu, Huseyin (advisor), Sehitoglu, Huseyin (Committee Chair), Bellon, Pascal (committee member), Krogstad, Jessica (committee member), Ertekin, Elif (committee member).
Subjects/Keywords: Shape Memory Alloys; High Entropy Alloys
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APA ·
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MLA ·
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CSE |
Export
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Manager
APA (6th Edition):
Wu, Y. (2019). Advanced experimental characterization of deformation mechanisms and temperature changes on novel alloys systems. (Doctoral Dissertation). University of Illinois – Urbana-Champaign. Retrieved from http://hdl.handle.net/2142/104757
Chicago Manual of Style (16th Edition):
Wu, Yan. “Advanced experimental characterization of deformation mechanisms and temperature changes on novel alloys systems.” 2019. Doctoral Dissertation, University of Illinois – Urbana-Champaign. Accessed April 11, 2021.
http://hdl.handle.net/2142/104757.
MLA Handbook (7th Edition):
Wu, Yan. “Advanced experimental characterization of deformation mechanisms and temperature changes on novel alloys systems.” 2019. Web. 11 Apr 2021.
Vancouver:
Wu Y. Advanced experimental characterization of deformation mechanisms and temperature changes on novel alloys systems. [Internet] [Doctoral dissertation]. University of Illinois – Urbana-Champaign; 2019. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/2142/104757.
Council of Science Editors:
Wu Y. Advanced experimental characterization of deformation mechanisms and temperature changes on novel alloys systems. [Doctoral Dissertation]. University of Illinois – Urbana-Champaign; 2019. Available from: http://hdl.handle.net/2142/104757
University of Utah
14.
Hackett, Kenneth Robert.
Phase constitution and mechanical properties of carbides in the Ta-C system.
Degree: MS;, Materials Science & Engineering;, 2009, University of Utah
URL: http://content.lib.utah.edu/cdm/singleitem/collection/etd2/id/1766/rec/883
► Carbides in the Ta-C system were prepared by hot-pressing mixed powders of TaC and Ta in C/Ta atomic ratios of TaCo.6, TaCo.7, TaCu.8, TaCo.9, and…
(more)
▼ Carbides in the Ta-C system were prepared by hot-pressing mixed powders of TaC and Ta in C/Ta atomic ratios of TaCo.6, TaCo.7, TaCu.8, TaCo.9, and TaCi.o at 1800 °C for 2 h. Rietveld analysis was performed on all compositions, and it was found that TaCo.6 was a mixture of 21% hexagonal close packed (HCP) a-Ta2C and 79% rhombohedral ^ - T a ^ - x , TaCo.7 was a mixture of 44.6% rhombohedral ^ - T a ^ - x and 55.4% face centered cubic (FCC) TaCy , TaCo.s and TaCo.9 were approximately 100% FCC TaCy , and TaC 1.0 was approximately 100% TaC. The TaC and TaCy compositions, produced were single phase with C/Ta ratios essentially the same as the starting nominal compositions and densities exceeding 96.5% of theoretical. Grain size decreased with increasing carbon deficiency from 1.0 to 0.8, with a corresponding increase in Vickers hardness from 13.5 to 20.0 GPa. The flexural strength, however, decreased from 650 to 500 MPa due to a decrease in fracture toughness from 5.3 to 3.8 MPaVm. Fracture toughness measured by single-edge-precracked-beam (SEPB) technique was exceptionally high (12.7 ± 0.7 MPaVm) for the a-Ta2C and ^ - T a ^ . x composition with a high weight percent of the ^ - T a ^ . x phase (~83 wt %). This disconnect between the change in hardness and strength indicates that the toughened compositions may exhibit R-curve behavior. Fracture surfaces were highly faceted with multiple cleavage crack planes and steps for TaCo.6 and TaCo.7. It is possible that the cleavage planes correspond to the stacking faults between the FCC and the HCP stacking layers within the stacking sequence ABABCACABCBC of the ^ - T a ^ . x phase bridge cracks in the crack wake with accompanying variations in local carbon concentrations fluctuating between TaCy and a-Ta2C.
Subjects/Keywords: Carbides; Tantalum alloys
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APA (6th Edition):
Hackett, K. R. (2009). Phase constitution and mechanical properties of carbides in the Ta-C system. (Masters Thesis). University of Utah. Retrieved from http://content.lib.utah.edu/cdm/singleitem/collection/etd2/id/1766/rec/883
Chicago Manual of Style (16th Edition):
Hackett, Kenneth Robert. “Phase constitution and mechanical properties of carbides in the Ta-C system.” 2009. Masters Thesis, University of Utah. Accessed April 11, 2021.
http://content.lib.utah.edu/cdm/singleitem/collection/etd2/id/1766/rec/883.
MLA Handbook (7th Edition):
Hackett, Kenneth Robert. “Phase constitution and mechanical properties of carbides in the Ta-C system.” 2009. Web. 11 Apr 2021.
Vancouver:
Hackett KR. Phase constitution and mechanical properties of carbides in the Ta-C system. [Internet] [Masters thesis]. University of Utah; 2009. [cited 2021 Apr 11].
Available from: http://content.lib.utah.edu/cdm/singleitem/collection/etd2/id/1766/rec/883.
Council of Science Editors:
Hackett KR. Phase constitution and mechanical properties of carbides in the Ta-C system. [Masters Thesis]. University of Utah; 2009. Available from: http://content.lib.utah.edu/cdm/singleitem/collection/etd2/id/1766/rec/883
University of Alberta
15.
Han, Chunfen.
Electrodeposition of Pb-free, Sn-based Alloy Solder
Films.
Degree: PhD, Department of Chemical and Materials
Engineering, 2009, University of Alberta
URL: https://era.library.ualberta.ca/files/8w32r639w
► The dominant materials used for solders in electronic assemblies over the past 60 years have been Pb-Sn alloys. Increasing pressure from environmental and health authorities…
(more)
▼ The dominant materials used for solders in electronic
assemblies over the past 60 years have been Pb-Sn alloys.
Increasing pressure from environmental and health authorities has
stimulated the development of various Pb-free solders. Two of the
most promising replacements are eutectic Sn-Cu and Sn-Ag-Cu alloys
that are produced primarily by electrodeposition. During soldering
and solid state aging (storage or in service of the electronic
assemblies), interactions take place at the solder/substrate metal
interface and form intermetallic compounds (IMCs) which are crucial
for the reliability of the solder joints. Simple and "green"
Sn-citrate and Sn-Cu-citrate solutions have been developed and
optimized to electrodeposit eutectic and near eutectic Sn-Cu solder
films. Sn-citrate suspensions with Cu particles and Sn-Cu-citrate
suspensions with Ag nano-particles have also been developed and
optimized to allow for electrochemical composite deposition of
eutectic and near eutectic Sn-Cu and Sn-Ag-Cu solder films.
Different plating and post-plating conditions, including solution
concentration, current density, agitation, additives, and aging,
have been investigated by evaluating their effects on plating rate,
deposit composition and microstructure. Tri-ammonium citrate is
used as the only complexing agent for Sn, Sn-Cu, and Sn-Ag-Cu
deposition. Speciation diagram calculations, reduction potential
calculations, and polarization studies are conducted to study
Sn-citrate solution chemistry and the kinetics of Sn
electrodeposition. X-ray photoelectron spectroscopy (XPS) analysis
is used to identify the precipitates formed in Sn-citrate solutions
at low pH. Current-controlled and potential-controlled
electrochemical techniques, nucleation modeling, and surface
morphology characterization techniques are applied to study the
nucleation and film growth mechanism of Sn and Sn-Cu
electrodeposition from Sn-citrate and Sn-Cu-citrate solutions.
Reflow and aging tests for deposited Sn-Cu and Sn-Ag-Cu solder
films on Cu and Ni substrates are performed to study the
interactions between the solder and the substrate and the formation
and growth of IMCs at the solder/substrate interface, by
characterizing the microstructure of the IMCs and calculating
diffusion coefficients.
Subjects/Keywords: Pb-Sn alloys
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APA ·
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MLA ·
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APA (6th Edition):
Han, C. (2009). Electrodeposition of Pb-free, Sn-based Alloy Solder
Films. (Doctoral Dissertation). University of Alberta. Retrieved from https://era.library.ualberta.ca/files/8w32r639w
Chicago Manual of Style (16th Edition):
Han, Chunfen. “Electrodeposition of Pb-free, Sn-based Alloy Solder
Films.” 2009. Doctoral Dissertation, University of Alberta. Accessed April 11, 2021.
https://era.library.ualberta.ca/files/8w32r639w.
MLA Handbook (7th Edition):
Han, Chunfen. “Electrodeposition of Pb-free, Sn-based Alloy Solder
Films.” 2009. Web. 11 Apr 2021.
Vancouver:
Han C. Electrodeposition of Pb-free, Sn-based Alloy Solder
Films. [Internet] [Doctoral dissertation]. University of Alberta; 2009. [cited 2021 Apr 11].
Available from: https://era.library.ualberta.ca/files/8w32r639w.
Council of Science Editors:
Han C. Electrodeposition of Pb-free, Sn-based Alloy Solder
Films. [Doctoral Dissertation]. University of Alberta; 2009. Available from: https://era.library.ualberta.ca/files/8w32r639w
16.
Rajan, Diwan Singh.
Corrosion characteristics of different metallic alloys in
acidic medium.
Degree: Chemistry, 2013, Shri Jagdishprasad Jhabarmal Tibarewala University
URL: http://shodhganga.inflibnet.ac.in/handle/10603/13916
► Corrosion is the disintegration or loss in useful properties of metal and their alloys or material of construction into its constituent atoms due to attack…
(more)
▼ Corrosion is the disintegration or loss in useful
properties of metal and their alloys or material of construction
into its constituent atoms due to attack of atmospheric gases
resulting in to chemical (dry corrosion) or electrochemical (wet
corrosion) reactions with its surroundings. Corrosion can also be
defined as an electrochemical process in which oxidation and
simultaneous reduction of metals takes place in a reaction in
presence of an oxidant such as oxygen. Dry and wet corrosion are
its two types. Formation of an oxides of metallic iron due to
oxidation in solid form is a well-known example of electrochemical
dry corrosion, commonly known as rusting. This type of loss of
material resulting in corrosion typically produces oxide(s) or
salt(s) of the original metal. Phenomenon of corrosion can not
avoided but losses due to corrosion can be minimized. Almost all
form of material corrodes in ways or other, such as ceramics
(concrete corrosion) or polymers, although in this context, the
term degradation is more commonly used. newlineCorrosion is also
defined as loss in the useful property of the material due to
attack of atmospheric gases. It can also be defined as the wearing
away (loss) of metals due to attack of atmospheric gases (air and
moisture) on the surface of metal and their alloys resulting in a
chemical or electrochemical reaction. newlineEffect of atmospheric
gases is different for different metallic alloys. Many structural
alloys corrodes severely while other mildly depending upon a number
of factors like humidity content, nature of pollutant, rate of flow
etc. The rate of corrosion can be strongly affected by exposure to
certain substances present in air. There are different forms of
corrosion. It can be concentrated locally to form a pit or crack,
or it can extended (spread) across a large area more or less
uniformly corroding the surface resulting in uniform type of
corrosion. Corrosion may be diffusion controlled process as it
occurs mainly on the exposed surfaces of material and their
alloys.
Summary p. 136-154, References p.
155-156
Advisors/Committee Members: Malik, Shiv Darshan.
Subjects/Keywords: Chemistry; Metallic alloys
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APA (6th Edition):
Rajan, D. S. (2013). Corrosion characteristics of different metallic alloys in
acidic medium. (Thesis). Shri Jagdishprasad Jhabarmal Tibarewala University. Retrieved from http://shodhganga.inflibnet.ac.in/handle/10603/13916
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Rajan, Diwan Singh. “Corrosion characteristics of different metallic alloys in
acidic medium.” 2013. Thesis, Shri Jagdishprasad Jhabarmal Tibarewala University. Accessed April 11, 2021.
http://shodhganga.inflibnet.ac.in/handle/10603/13916.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Rajan, Diwan Singh. “Corrosion characteristics of different metallic alloys in
acidic medium.” 2013. Web. 11 Apr 2021.
Vancouver:
Rajan DS. Corrosion characteristics of different metallic alloys in
acidic medium. [Internet] [Thesis]. Shri Jagdishprasad Jhabarmal Tibarewala University; 2013. [cited 2021 Apr 11].
Available from: http://shodhganga.inflibnet.ac.in/handle/10603/13916.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Rajan DS. Corrosion characteristics of different metallic alloys in
acidic medium. [Thesis]. Shri Jagdishprasad Jhabarmal Tibarewala University; 2013. Available from: http://shodhganga.inflibnet.ac.in/handle/10603/13916
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Texas A&M University
17.
Guiza-Arguello, Viviana R.
Evaluation of Biomimetic and Alloy-based Materials for Orthopedic Applications.
Degree: PhD, Chemical Engineering, 2013, Texas A&M University
URL: http://hdl.handle.net/1969.1/151159
► The basic principle of tissue engineering is the combination of appropriate cells with biomaterials under conditions that promote and lead to tissue formation. A tissue…
(more)
▼ The basic principle of tissue engineering is the combination of appropriate cells with biomaterials under conditions that promote and lead to tissue formation. A tissue engineering scaffold is a material that supports cells for their growth, proliferation, and differentiation in the absence of native extracellular matrix (ECM). The ECM was originally thought to provide primarily a mechanical support for the cells, but through receptors on the surface of cells, the ECM takes part in promoting cell adhesion, migration, growth, differentiation, and apoptosis. Ideally, a tissue engineered scaffold should mimic both the form and function of native ECM. Additionally, like any other biomaterial for implantation, a tissue engineered scaffold should be biocompatible and not initiate tissue reactions or immune responses.
This work focuses on the evaluation of the biocompatibility of novel alloy-based materials for orthopedic applications. In addition, in the context of bone regeneration, it examines the influence of select native ECM constituents on mesenchymal stem cell (MSC) osteogenic differentiation in 3-D contexts. On the other hand, given the crucial role of vasculogenesis in cell nutrition in the scaffolds, ECM mimics found to support osteogenesis were further evaluated for endothelial cell adhesion and migration. For the hydrogel systems presented in this manuscript, poly(ethylene glycol) diacrylate (PEGDA) networks were selected as the base scaffold due to the broad tunability of their mechanical properties and their previous use in bone regeneration applications. In addition, pure PEGDA hydrogels do not intrinsically promote cell adhesion. Thus, cell interactions with PEGDA gels are initially isolated to the interactions supported by the proteins tethered to the scaffold.
This work attempts to contribute to the development of novel materials that provide biocompatibility and enhanced versatility in orthopedic applications. Moreover, in the context of bone regeneration, the use of selective ECM biomolecules in hybrid hydrogel scaffolds will aid in the understanding of MSC osteogenic responses to specific ECM constituents. Additionally, incorporation of ECM mimics that support both osteogenesis and vasculogenesis will provide a more controlled platform which will serve as a foundation for the fabrication of more efficient vascularized bone constructs.
Advisors/Committee Members: Hahn, Mariah (advisor), Grunlan, Melissa (committee member), Kao, Katy (committee member), Ugaz, Victor (committee member).
Subjects/Keywords: Extracellular Matrix; Alloys
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APA (6th Edition):
Guiza-Arguello, V. R. (2013). Evaluation of Biomimetic and Alloy-based Materials for Orthopedic Applications. (Doctoral Dissertation). Texas A&M University. Retrieved from http://hdl.handle.net/1969.1/151159
Chicago Manual of Style (16th Edition):
Guiza-Arguello, Viviana R. “Evaluation of Biomimetic and Alloy-based Materials for Orthopedic Applications.” 2013. Doctoral Dissertation, Texas A&M University. Accessed April 11, 2021.
http://hdl.handle.net/1969.1/151159.
MLA Handbook (7th Edition):
Guiza-Arguello, Viviana R. “Evaluation of Biomimetic and Alloy-based Materials for Orthopedic Applications.” 2013. Web. 11 Apr 2021.
Vancouver:
Guiza-Arguello VR. Evaluation of Biomimetic and Alloy-based Materials for Orthopedic Applications. [Internet] [Doctoral dissertation]. Texas A&M University; 2013. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/1969.1/151159.
Council of Science Editors:
Guiza-Arguello VR. Evaluation of Biomimetic and Alloy-based Materials for Orthopedic Applications. [Doctoral Dissertation]. Texas A&M University; 2013. Available from: http://hdl.handle.net/1969.1/151159
University of Johannesburg
18.
Mochele, Julius Thabiso.
Magnetoelasticity of ternary Cr-Ru-Mo alloys.
Degree: 2012, University of Johannesburg
URL: http://hdl.handle.net/10210/7610
► M.Sc.
Alloying Cr with non-magnetic Ru, results in unusual magnetoelastic effects due to strong magnetic interactions with the lattice. In the low concentration region, Ru…
(more)
▼ M.Sc.
Alloying Cr with non-magnetic Ru, results in unusual magnetoelastic effects due to strong magnetic interactions with the lattice. In the low concentration region, Ru increases the Neél temperature TN due to the enhancement of the spin density wave (SDW). The temperature dependence of the thermal expansion coefficient (a) of Cr o.997Ru0.003 displays Invar behaviour within a small temperature region (7.-: 5 K) of the magnetic transition at TN 390 K). This alloy is of little practical use since the Invar behaviour is well above room temperature. Mo, which is isoelectronic with Cr, is known to vary the strength of the SDW in Cr without changing its basic nature. It reduces and broadens the magnetic transition at TN of Cr and its alloys. Therefore Mo seems to be suitable for tayloring the Cr 0.997R110.003 alloy system, reducing the temperature region, in which the Invar effects are observed, down to room temperature. The temperature dependence of the thermal expansion and of the elastic constants were measured for (Cr i _rMor )0.997Ruo.003 and (Cri _yMoy )0.995Ru0.005 in the temperature range between 77 K and 450 K so that the effects of Mo on the Invar behaviour of Cr 0.997Ru0.003 and on the magnetoelasticity in (Cr i„Moz )0.997Ru0.003 and (Cr i _yMoy )0.995Ru0.005 could be studied. From the Invar-study we learn that although the addition of Mo to Cro.997Rno.003 succesfully decreased the Neel temperature down to room temperature, it simultaneously increased the coefficient of thermal expansion to much larger values. We were therefore not successful in our effort to improve the Invar type properties of the Cr0.997R110.003 alloy by the addition of Mo. Although the study was mainly focussed on tayloring the antiferromagnetic Invar Cr o.997Ru0.003 alloy with Mo, we also theoretically analysed the effects on the magnetoelasticity of Cr0.997Ru0.003, in terms of the temperature dependences of the thermal expansion and elastic constants in (Cri_xMox)0.997Ruo.003 and (Cri— yMoy )o.99sRuo.00s alloy systems when some of Cr atoms are replaced by those of Mo. In both Cr-Ru-Mo alloy systems, a(T) showed well defined anomalies with a minimum at the commensurate (C) SDW to paramagnetic (P) phase transition at TN and a maximum in the incommensurate (I) SDW-CSDW transition at T IC for x < 0.015 and y = 0.01. For x > 0.015, the CSDW state is completely suppressed and only the ISDW-P phase transition at TN is observed. The temperature dependence of the elastic constants in (Cri,M0x)o.997Ruo.003 with x = 0.015 and 0.07 showed only the ISDW-P phase transition, while the alloy with x = 0.007 showed both the CSDW-P at TN and a very small ISDW-CSDW transition at Ti.c . In general: Mo decreases the magnetic contributions to the volume and to the bulk modulus of Cr0.997Ru0.003 below TN . Mo completely suppresses the CSDW state of Cr0.997R11 0.003. The (Cri„Mos )0.997Ruo .003 and (Cri _yMoy )0 .995Ru0.005 show a second order phase transition at TN . Hysteresis effects were observed in (Cri—xMox)o.997Ruo.003 at the ISDW-CSDW phase…
Subjects/Keywords: Ternary alloys; Magnetostriction
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APA (6th Edition):
Mochele, J. T. (2012). Magnetoelasticity of ternary Cr-Ru-Mo alloys. (Thesis). University of Johannesburg. Retrieved from http://hdl.handle.net/10210/7610
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Mochele, Julius Thabiso. “Magnetoelasticity of ternary Cr-Ru-Mo alloys.” 2012. Thesis, University of Johannesburg. Accessed April 11, 2021.
http://hdl.handle.net/10210/7610.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Mochele, Julius Thabiso. “Magnetoelasticity of ternary Cr-Ru-Mo alloys.” 2012. Web. 11 Apr 2021.
Vancouver:
Mochele JT. Magnetoelasticity of ternary Cr-Ru-Mo alloys. [Internet] [Thesis]. University of Johannesburg; 2012. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/10210/7610.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Mochele JT. Magnetoelasticity of ternary Cr-Ru-Mo alloys. [Thesis]. University of Johannesburg; 2012. Available from: http://hdl.handle.net/10210/7610
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
University of Johannesburg
19.
Reddy, Leelakrishna.
Antiferromagnetic and quantum critical behaviour of the (Cr86Ru14)1–x(V,Mn)x alloy system.
Degree: 2011, University of Johannesburg
URL: http://hdl.handle.net/10210/3826
► M.Sc.
An experimental study on the magnetic properties of the (Cr86Ru14)1–x(V,Mn)x alloy system is reported in this thesis. The work focusses mainly on two aspects…
(more)
▼ M.Sc.
An experimental study on the magnetic properties of the (Cr86Ru14)1–x(V,Mn)x alloy system is reported in this thesis. The work focusses mainly on two aspects of the magnetic behaviour of this alloy system; firstly that of the base alloy Cr86Ru14 having a Ru concentration on the magnetic phase diagram of the Cr-Ru system that is close to a putative quantum critical point (QCP) (xc ≈ 17 at.% Ru), and secondly, of the effects of tuning this base alloy towards (V-addition) or away (Mn-addition) from the QCP. For the Cr86Ru14 base alloy, measurements of the electrical resistivity and elastic constants as functions of temperature and pressure are reported. These are supplemented by thermal expansion and neutron diffraction measurements as a function of temperature through the Néel transition temperature, TN.
Subjects/Keywords: Alloys - Magnetic properties
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APA (6th Edition):
Reddy, L. (2011). Antiferromagnetic and quantum critical behaviour of the (Cr86Ru14)1–x(V,Mn)x alloy system. (Thesis). University of Johannesburg. Retrieved from http://hdl.handle.net/10210/3826
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Reddy, Leelakrishna. “Antiferromagnetic and quantum critical behaviour of the (Cr86Ru14)1–x(V,Mn)x alloy system.” 2011. Thesis, University of Johannesburg. Accessed April 11, 2021.
http://hdl.handle.net/10210/3826.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Reddy, Leelakrishna. “Antiferromagnetic and quantum critical behaviour of the (Cr86Ru14)1–x(V,Mn)x alloy system.” 2011. Web. 11 Apr 2021.
Vancouver:
Reddy L. Antiferromagnetic and quantum critical behaviour of the (Cr86Ru14)1–x(V,Mn)x alloy system. [Internet] [Thesis]. University of Johannesburg; 2011. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/10210/3826.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Reddy L. Antiferromagnetic and quantum critical behaviour of the (Cr86Ru14)1–x(V,Mn)x alloy system. [Thesis]. University of Johannesburg; 2011. Available from: http://hdl.handle.net/10210/3826
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Nelson Mandela Metropolitan University
20.
Abbas, Abdalla Abbas Said.
Machinability of rapidly solidified aluminium alloy for optical applications.
Degree: 2020, Nelson Mandela Metropolitan University
URL: http://hdl.handle.net/10948/45975
► The production of metal mirrors and critical components for optical devices and aerospace application requires extreme high accuracy and outstanding surface quality. Thus, to achieve…
(more)
▼ The production of metal mirrors and critical components for optical devices and aerospace application requires extreme high accuracy and outstanding surface quality. Thus, to achieve such high dimensional accuracies, they are being mainly produced through ultra-high precision machining. Aluminium alloys have been used in the production of components for optics application as well as spaceborne for so many years but with the advancement in technology and demands for a superior material, a new modified grade of aluminium was developed by a rapid solidification process. These grades exhibit a much better mechanical and physical properties while having a finer microstructure. The only downside is the limited research in the correlation of surface roughness and reflectance when single point diamond turned. In this study, rapidly solidified aluminium RSA 905 were used to investigate the effect of varying the cutting parameters on the machined surface finish and its corresponding surface reflectance. The cutting parameters were cutting speed, feed rate and depth of cut. The surface roughness was measured using Taylor Hopson PGI Profilometer while the reflectance factor was measured by using VERTEX 80v Spectrometer. The results were used to develop two predictive models namely; response surface and artificial neural network which have indicated a very high accuracy to the experimental measurements. Finally, the results were very promising for the diamond turning of RSA 905 where it has achieved a very low values of surface roughness and high reflectance in the visual range without the need of any additional production/fabrication steps and to ensure that bi-metallic binding does not take place in extreme low temperatures. Therefore, RSA 905 is a very promising material for optical applications in the visual spectrum.
Subjects/Keywords: Aluminum alloys; Mechatronics
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Export
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APA (6th Edition):
Abbas, A. A. S. (2020). Machinability of rapidly solidified aluminium alloy for optical applications. (Thesis). Nelson Mandela Metropolitan University. Retrieved from http://hdl.handle.net/10948/45975
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Chicago Manual of Style (16th Edition):
Abbas, Abdalla Abbas Said. “Machinability of rapidly solidified aluminium alloy for optical applications.” 2020. Thesis, Nelson Mandela Metropolitan University. Accessed April 11, 2021.
http://hdl.handle.net/10948/45975.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
MLA Handbook (7th Edition):
Abbas, Abdalla Abbas Said. “Machinability of rapidly solidified aluminium alloy for optical applications.” 2020. Web. 11 Apr 2021.
Vancouver:
Abbas AAS. Machinability of rapidly solidified aluminium alloy for optical applications. [Internet] [Thesis]. Nelson Mandela Metropolitan University; 2020. [cited 2021 Apr 11].
Available from: http://hdl.handle.net/10948/45975.
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Council of Science Editors:
Abbas AAS. Machinability of rapidly solidified aluminium alloy for optical applications. [Thesis]. Nelson Mandela Metropolitan University; 2020. Available from: http://hdl.handle.net/10948/45975
Note: this citation may be lacking information needed for this citation format:
Not specified: Masters Thesis or Doctoral Dissertation
Delft University of Technology
21.
Poluru, Madhav (author).
Determination of microstructural properties and its effects on hardness of FeNiCrCoAlx (x=0,20 at%) high entropy alloys.
Degree: 2017, Delft University of Technology
URL: http://resolver.tudelft.nl/uuid:2fcf5cd5-e0a2-4fec-9907-c40fdf69f8e4
► In recent years, the concept of high entropy alloys (HEAs) has gained increasing attention due to their unique compositions, microstructures and properties. High entropy alloys…
(more)
▼ In recent years, the concept of high entropy
alloys (HEAs) has gained increasing attention due to their unique compositions, microstructures and properties. High entropy
alloys are defined as solid-solution
alloys with 5 or more principal elements in equal or nearly equal atomic fractions with the elemental concentrations ranging from 5 – 35at%. This new class of materials are considered to be potential alternatives to the conventional materials which are currently being used in the different fields such as structural, nuclear, automotive and aerospace industries. In this study, the determination of phases and microstructural properties of FeNiCrCo and FeNiCrCoAl high entropy
alloys with nearly equi-atomic concentrations and their influence on the hardness of the material after undergoing different thermo-mechanical treatments was studied. The combination of different techniques such as, X-ray diffraction (XRD), Energy dispersive spectroscopy (EDS) and Electron backscattered diffraction (EBSD) were used to determine the phases present in the alloy systems for different experimental conditions. Optical microscopy, scanning electron microscope (SEM) were used to observe the microstructural evolution in the material. Vickers hardness tester is used to determine the hardness values. FeNiCrCo high entropy alloy system was found out to be a single-phase FCC system for all experimental conditions whereas FeNiCrCoAl contains a mixture of BCC, FCC and Sigma phases. The hardness values were correlated to the phases present and the microstructural properties of the alloy. This study provides an overview of the behavior of these alloy systems from intermediate to high temperature range for two different starting conditions, as cast and hot rolled. This work can be considered as a first step to fully understanding the potential of these high entropy alloy systems to serve as potential alternatives to the conventional
alloys currently used.
Advisors/Committee Members: Sietsma, Jilt (mentor), Delft University of Technology (degree granting institution).
Subjects/Keywords: High Entropy Alloys
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APA (6th Edition):
Poluru, M. (. (2017). Determination of microstructural properties and its effects on hardness of FeNiCrCoAlx (x=0,20 at%) high entropy alloys. (Masters Thesis). Delft University of Technology. Retrieved from http://resolver.tudelft.nl/uuid:2fcf5cd5-e0a2-4fec-9907-c40fdf69f8e4
Chicago Manual of Style (16th Edition):
Poluru, Madhav (author). “Determination of microstructural properties and its effects on hardness of FeNiCrCoAlx (x=0,20 at%) high entropy alloys.” 2017. Masters Thesis, Delft University of Technology. Accessed April 11, 2021.
http://resolver.tudelft.nl/uuid:2fcf5cd5-e0a2-4fec-9907-c40fdf69f8e4.
MLA Handbook (7th Edition):
Poluru, Madhav (author). “Determination of microstructural properties and its effects on hardness of FeNiCrCoAlx (x=0,20 at%) high entropy alloys.” 2017. Web. 11 Apr 2021.
Vancouver:
Poluru M(. Determination of microstructural properties and its effects on hardness of FeNiCrCoAlx (x=0,20 at%) high entropy alloys. [Internet] [Masters thesis]. Delft University of Technology; 2017. [cited 2021 Apr 11].
Available from: http://resolver.tudelft.nl/uuid:2fcf5cd5-e0a2-4fec-9907-c40fdf69f8e4.
Council of Science Editors:
Poluru M(. Determination of microstructural properties and its effects on hardness of FeNiCrCoAlx (x=0,20 at%) high entropy alloys. [Masters Thesis]. Delft University of Technology; 2017. Available from: http://resolver.tudelft.nl/uuid:2fcf5cd5-e0a2-4fec-9907-c40fdf69f8e4
University of Aberdeen
22.
Majchrowski, Tomasz P.
Chemical behaviour of a nuclear-grade magnesium alloy during storage.
Degree: PhD, 2015, University of Aberdeen
URL: https://abdn.alma.exlibrisgroup.com/view/delivery/44ABE_INST/12153178290005941
;
https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.655668
► Magnox, a magnesium alloy, was specifically developed in early 1950s for use as a fuel cladding in the British first generation nuclear civilian reactors. Magnesium…
(more)
▼ Magnox, a magnesium alloy, was specifically developed in early 1950s for use as a fuel cladding in the British first generation nuclear civilian reactors. Magnesium metal demonstrates outstanding properties for use as a nuclear fuel cladding; however, it has an intrinsic ability to undergo oxidation. This introduces significant limitations during aqueous storage required prior to reprocessing of the spent fuel. A possibility exists for a failure of the dated reprocessing facilities, and therefore this may require for the spent fuel to be kept in the aqueous storage for an extended period of time. In a most extreme case, the corrosion of the fuel cladding may lead to a contamination of the storage facilities with hazardous radioactive fission species and corrosion products. A comprehensive study of chemical behaviour of the Magnox alloy may allow a deeper understanding of the reactivity of the cladding and lead to improvements in management of storage of spent Magnox fuel, thus preventing corrosion induced leakage of hazardous products. The understanding of chemistry of the Magnox alloy during storage may be improved by the development of a novel approach to study corrosion reactions. Infrared spectroscopy and Raman spectroscopy are widely used to study properties of surfaces. In addition, electron microscopy provides with information on the structure and physical appearance of materials. The results show clear evidence for reactivity of the alloy to be greatly influenced by changes induced by nature of cooling processes upon simulated discharge of spent Magnox fuel from a reactor. It is evident that the fast cooling process using water introduces the most deleterious change to the properties of the material. It is understood that presence of water provides with favourable conditions for oxidation of the metal to take place. Opposite effect is observed with slow cooling under an atmosphere of carbon dioxide gas. Further studies using X-ray diffraction suggest that crystallinity of the alloy is increased during simulated reactor exposure and phase segregation takes place during cooling. The latter appears to be dependent on the nature of the cooling process, and thus as a result different strains are applied. Through the studies it is shown that the pond conditions also contribute to control of the behaviour of the fuel cladding. A series of experiments demonstrated that sodium carbonate offers paramount corrosion protection when compared to sodium hydroxide. Systematic investigations allowed for a complete corrosion mechanism of the Magnox cladding to be drawn. It is demonstrated that the effects of present as well past conditions should be assessed and taken into consideration when establishing chemical behaviour of a material.
Subjects/Keywords: 540; Magnesium alloys
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APA (6th Edition):
Majchrowski, T. P. (2015). Chemical behaviour of a nuclear-grade magnesium alloy during storage. (Doctoral Dissertation). University of Aberdeen. Retrieved from https://abdn.alma.exlibrisgroup.com/view/delivery/44ABE_INST/12153178290005941 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.655668
Chicago Manual of Style (16th Edition):
Majchrowski, Tomasz P. “Chemical behaviour of a nuclear-grade magnesium alloy during storage.” 2015. Doctoral Dissertation, University of Aberdeen. Accessed April 11, 2021.
https://abdn.alma.exlibrisgroup.com/view/delivery/44ABE_INST/12153178290005941 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.655668.
MLA Handbook (7th Edition):
Majchrowski, Tomasz P. “Chemical behaviour of a nuclear-grade magnesium alloy during storage.” 2015. Web. 11 Apr 2021.
Vancouver:
Majchrowski TP. Chemical behaviour of a nuclear-grade magnesium alloy during storage. [Internet] [Doctoral dissertation]. University of Aberdeen; 2015. [cited 2021 Apr 11].
Available from: https://abdn.alma.exlibrisgroup.com/view/delivery/44ABE_INST/12153178290005941 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.655668.
Council of Science Editors:
Majchrowski TP. Chemical behaviour of a nuclear-grade magnesium alloy during storage. [Doctoral Dissertation]. University of Aberdeen; 2015. Available from: https://abdn.alma.exlibrisgroup.com/view/delivery/44ABE_INST/12153178290005941 ; https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.655668
23.
Rahman, A. H. M. Esfakur.
Transient Liquid Phase Bonding of Titanium-, Iron- and Nickel- Based Alloys.
Degree: PhD, Mechanical Engineering, 2013, University of North Dakota
URL: https://commons.und.edu/theses/885
► The operating temperature of land-based gas turbines and jet engines are ever-increasing to increase the efficiency, decrease the emissions and minimize the cost. Within…
(more)
▼ The operating temperature of land-based gas turbines and jet engines are ever-increasing to increase the efficiency, decrease the emissions and minimize the cost. Within the engines, complex-shaped parts experience extreme temperature, fatigue and corrosion conditions. Ti-based, Ni-based and Fe-based
alloys are commonly used in gas turbines and jet engines depending on the temperatures of different sections. Although those
alloys have superior mechanical, high temperature and corrosion properties, severe operating conditions cause fast degradation and failure of the components. Repair of these components could reduce lifecycle costs. Unfortunately, conventional fusion welding is not very attractive, because Ti reacts very easily with oxygen and nitrogen at high temperatures, Ni-based superalloys show heat affected zone (HAZ) cracking, and stainless steels show intergranular corrosion and knife-line attack. On the other hand, transient liquid phase (TLP) bonding method has been considered as preferred joining method for those types of
alloys.
During the initial phase of the current work commercially pure Ti, Fe and Ni were diffusion bonded using commercially available interlayer materials. Commercially pure Ti (Ti-grade 2) has been diffusion bonded using silver and copper interlayers and without any interlayer. With a silver (Ag) interlayer, different intermetallics (AgTi, AgTh) appeared in the joint centerline microstructure. While with a Cu interlayer eutectic mixtures and Ti-Cu solid solutions appeared in the joint centerline. The maximum tensile strengths achieved were 160 MPa, 502 MPa, and 3 82 MP a when Ag, Cu and no interlayers were used, respectively. Commercially pure Fe ( cp-F e) was diffusion bonded using Cu (25 m) and Au-12Ge eutectic interlayer (100 μm). Cu diffused predominantly along austenite grain boundaries in all bonding conditions. Residual interlayers appeared at lower bonding temperature and time, however, voids were observed in the joint centerline at higher joining temperature and time. Dispersed Au-rich particles were observed in the base metal near interface. The highest ultimate tensile strengths obtained for the bonded Fe were 291±2 MPa using a Cu interlayer at 1030°C for 10 hand 315±4 MPa using a Au-12Ge interlayer at 950°C for 15 h. Commercially pure Ni (cp-Ni) was diffusion bonded using a Al, Au-12Ge or Cu interlayer. The formation of intermetallics could not be avoided when Al interlayer was used. Even though no intermetallics were obtained with Au-12Ge or Cu interlayer, appreciable strength of the joint was not found.
Next, the simple bonding systems were modeled numerically. It is hoped that the simple models can be extended for higher order
alloys. The modeling of TLP joint means to come up with a mathematical model which can predict the concentration profiles of diffusing species. The concentration dependence of diffusivity in a multi-component diffusion system makes it complicated to predict the concentration profiles of diffusing species. The so-called chemical…
Advisors/Committee Members: Dr. Matthew N. Cavalli.
Subjects/Keywords: Diffusion bonding; titanium alloys; iron alloys; nickel alloys; Engineering
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APA (6th Edition):
Rahman, A. H. M. E. (2013). Transient Liquid Phase Bonding of Titanium-, Iron- and Nickel- Based Alloys. (Doctoral Dissertation). University of North Dakota. Retrieved from https://commons.und.edu/theses/885
Chicago Manual of Style (16th Edition):
Rahman, A H M Esfakur. “Transient Liquid Phase Bonding of Titanium-, Iron- and Nickel- Based Alloys.” 2013. Doctoral Dissertation, University of North Dakota. Accessed April 11, 2021.
https://commons.und.edu/theses/885.
MLA Handbook (7th Edition):
Rahman, A H M Esfakur. “Transient Liquid Phase Bonding of Titanium-, Iron- and Nickel- Based Alloys.” 2013. Web. 11 Apr 2021.
Vancouver:
Rahman AHME. Transient Liquid Phase Bonding of Titanium-, Iron- and Nickel- Based Alloys. [Internet] [Doctoral dissertation]. University of North Dakota; 2013. [cited 2021 Apr 11].
Available from: https://commons.und.edu/theses/885.
Council of Science Editors:
Rahman AHME. Transient Liquid Phase Bonding of Titanium-, Iron- and Nickel- Based Alloys. [Doctoral Dissertation]. University of North Dakota; 2013. Available from: https://commons.und.edu/theses/885
24.
SORDI, LAURA.
Estudo da transicao ordem-desordem em ligas de FeNi com impurezas.
Degree: 1969, Brazil
URL: http://repositorio.ipen.br:8080/xmlui/handle/123456789/9138
► Made available in DSpace on 2014-10-09T12:23:59Z (GMT). No. of bitstreams: 0
Made available in DSpace on 2014-10-09T14:07:58Z (GMT). No. of bitstreams: 1 01070.pdf: 2677585 bytes,…
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▼ Made available in DSpace on 2014-10-09T12:23:59Z (GMT). No. of bitstreams: 0
Made available in DSpace on 2014-10-09T14:07:58Z (GMT). No. of bitstreams: 1 01070.pdf: 2677585 bytes, checksum: 886f210d3f6431136fa09330d68b8fa2 (MD5)
Dissertacao (Mestrado)
IEA/D
Faculdade de Filosofia Letras e Ciencias Humanas, Universidade de Sao Paulo - FFLCH/USP
Advisors/Committee Members: Luiz Guimaraes Ferreira.
Subjects/Keywords: alloys; iron alloys; nickel alloys
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APA (6th Edition):
SORDI, L. (1969). Estudo da transicao ordem-desordem em ligas de FeNi com impurezas. (Masters Thesis). Brazil. Retrieved from http://repositorio.ipen.br:8080/xmlui/handle/123456789/9138
Chicago Manual of Style (16th Edition):
SORDI, LAURA. “Estudo da transicao ordem-desordem em ligas de FeNi com impurezas.” 1969. Masters Thesis, Brazil. Accessed April 11, 2021.
http://repositorio.ipen.br:8080/xmlui/handle/123456789/9138.
MLA Handbook (7th Edition):
SORDI, LAURA. “Estudo da transicao ordem-desordem em ligas de FeNi com impurezas.” 1969. Web. 11 Apr 2021.
Vancouver:
SORDI L. Estudo da transicao ordem-desordem em ligas de FeNi com impurezas. [Internet] [Masters thesis]. Brazil; 1969. [cited 2021 Apr 11].
Available from: http://repositorio.ipen.br:8080/xmlui/handle/123456789/9138.
Council of Science Editors:
SORDI L. Estudo da transicao ordem-desordem em ligas de FeNi com impurezas. [Masters Thesis]. Brazil; 1969. Available from: http://repositorio.ipen.br:8080/xmlui/handle/123456789/9138
25.
AMBROZIO FILHO, FRANCISCO.
Microestruturas de solidificacao de ligas aluminio-uranio.
Degree: 1973, Brazil
URL: http://repositorio.ipen.br:8080/xmlui/handle/123456789/9065
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Dissertacao (Mestrado)
IEA/D
Escola Politecnica, Universidade de Sao Paulo - POLI/USP
Advisors/Committee Members: Renato Rocha Vieira.Subjects/Keywords: alloys; uranium alloys; aluminium alloys
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APA (6th Edition):
AMBROZIO FILHO, F. (1973). Microestruturas de solidificacao de ligas aluminio-uranio. (Masters Thesis). Brazil. Retrieved from http://repositorio.ipen.br:8080/xmlui/handle/123456789/9065
Chicago Manual of Style (16th Edition):
AMBROZIO FILHO, FRANCISCO. “Microestruturas de solidificacao de ligas aluminio-uranio.” 1973. Masters Thesis, Brazil. Accessed April 11, 2021.
http://repositorio.ipen.br:8080/xmlui/handle/123456789/9065.
MLA Handbook (7th Edition):
AMBROZIO FILHO, FRANCISCO. “Microestruturas de solidificacao de ligas aluminio-uranio.” 1973. Web. 11 Apr 2021.
Vancouver:
AMBROZIO FILHO F. Microestruturas de solidificacao de ligas aluminio-uranio. [Internet] [Masters thesis]. Brazil; 1973. [cited 2021 Apr 11].
Available from: http://repositorio.ipen.br:8080/xmlui/handle/123456789/9065.
Council of Science Editors:
AMBROZIO FILHO F. Microestruturas de solidificacao de ligas aluminio-uranio. [Masters Thesis]. Brazil; 1973. Available from: http://repositorio.ipen.br:8080/xmlui/handle/123456789/9065
Indian Institute of Science
26.
Sen, Indrani.
Mechanical Behavior Of B-Modified Ti-6Al-4V Alloys.
Degree: PhD, Faculty of Engineering, 2011, Indian Institute of Science
URL: http://etd.iisc.ac.in/handle/2005/1430
► Titanium alloys are important engineering alloys that are extensively used in various industries. This is due to their unique combination of mechanical and physical properties…
(more)
▼ Titanium
alloys are important engineering
alloys that are extensively used in various industries. This is due to their unique combination of mechanical and physical properties such as low density combined with high strength and toughness as well as outstanding corrosion resistance. An additional benefit associated with Ti
alloys, in general, is that their properties are relatively temperature-insensitive between cryogenic temperature and ~500 °C. Amongst the Ti
alloys, Ti-6Al-4V (referred as Ti64) is a widely used alloy. Conventionally cast Ti64 possesses classical Widmanstätten microstructure of (hcp) α and (bcc) β phases. However this microstructure suffers from large prior β grain size, which tends be in the order of a few mm. Such large grain sizes are associated with poor processability as well as inferior mechanical performance. The necessity to break this coarse as-cast microstructure down, through several successive thermo-mechanical processing steps, adds considerably to the cost of finished Ti alloy products, making them expensive vis-à-vis other competing
alloys.
The addition of small amount of B (~0.1%) to Ti64
alloys, on the other hand reduces the cast grain size from couple of mm to ~200 µm. Moreover, addition of B to Ti
alloys produces the intermetallic TiB needles during solidification by an in situ chemical reaction. The overall objective of this work is to gain insights into the role of microstructural modifications, induced by B addition to Ti64, on the mechanical performance of the
alloys, in particular the room temperature damage tolerance (fracture toughness and fatigue crack growth) characteristics. The key questions we seek to answer through this study are the following: (a) What role does the microstructural refinement plays on the quasistatic as well as fracture and fatigue behavior and high temperature deformability of the
alloys? (c) A hierarchy of microstructural length scales exist in Ti
alloys. These are the lath, colony and grain sizes. Which of these microstructural parameters control the mechanical performance of the alloy? (b) What (possibly detrimental) role, if any, do the TiB needles play in influencing the mechanical performance of Ti64
alloys? This is because TiB being much stiffer, strain incompatibility between the matrix and the TiB phase could lead to easy nucleation of cracks during cyclic loading as well as can pose problems during dynamic deformation. (d) What is the optimum amount of B that can be added to Ti64 such that the most desirable combination of properties can be achieved?
Five B-modified Ti64
alloys with B content varying from 0.0 to 0.55 wt.% were utilised to answer the above questions. Marked prior β grain size reduction was noted with up to 0.1 wt.% B addition. Simultaneous refinement of α/β colony size has also been observed. The addition of B to Ti64, on the other hand increases the α lath size. The TiB needles that form in-situ during casting are arranged in a necklace like structure surrounding the grain boundaries for higher B added Ti64
alloys.
An…
Advisors/Committee Members: Ramamurty, U (advisor).
Subjects/Keywords: Titanium Alloys - Mechanical Properties; Titanium Alloys - Fatigue; Titanium Alloys - Aerospace Applications; Titaniuim Alloys - Deformation; Titanium Alloys - Microstructure; Titanium Alloys - Tensile Behavior; Fracture Mechanics; Ti Alloys; Metallurgy
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APA (6th Edition):
Sen, I. (2011). Mechanical Behavior Of B-Modified Ti-6Al-4V Alloys. (Doctoral Dissertation). Indian Institute of Science. Retrieved from http://etd.iisc.ac.in/handle/2005/1430
Chicago Manual of Style (16th Edition):
Sen, Indrani. “Mechanical Behavior Of B-Modified Ti-6Al-4V Alloys.” 2011. Doctoral Dissertation, Indian Institute of Science. Accessed April 11, 2021.
http://etd.iisc.ac.in/handle/2005/1430.
MLA Handbook (7th Edition):
Sen, Indrani. “Mechanical Behavior Of B-Modified Ti-6Al-4V Alloys.” 2011. Web. 11 Apr 2021.
Vancouver:
Sen I. Mechanical Behavior Of B-Modified Ti-6Al-4V Alloys. [Internet] [Doctoral dissertation]. Indian Institute of Science; 2011. [cited 2021 Apr 11].
Available from: http://etd.iisc.ac.in/handle/2005/1430.
Council of Science Editors:
Sen I. Mechanical Behavior Of B-Modified Ti-6Al-4V Alloys. [Doctoral Dissertation]. Indian Institute of Science; 2011. Available from: http://etd.iisc.ac.in/handle/2005/1430
Indian Institute of Science
27.
Radhakrishnan, Madhavan.
Role Of Stacking Fault Energy On Texture Evolution In Micro- And Nano-Crystalline Nickel-Cobalt Alloys.
Degree: PhD, Faculty of Engineering, 2017, Indian Institute of Science
URL: http://etd.iisc.ac.in/handle/2005/2623
► Plastic deformation of metals and alloys are invariably accompanied by the development of texture. The origin of texture is attributed to the deformation micro-mechanisms associated…
(more)
▼ Plastic deformation of metals and
alloys are invariably accompanied by the development of texture. The origin of texture is attributed to the deformation micro-mechanisms associated with processing. The face-centered cubic (FCC) metals and
alloys are known to exhibit two distinct types of textures when subjected to large strain rolling deformation, namely, (i) Cu-type texture, commonly seen in high/medium stacking fault energy (SFE) materials, (ii) Bs-type texture in low SFE materials. The circumstances that could result in the formation of Bs-type texture in low SFE materials still remains an open question and no definite mechanism has been uniquely agreed upon.
Apart from the SFE, grain size could also influence the deformation mechanism and hence the deformation texture. It is well known that in materials with grain sizes less than 100 nm (referred to as nano-crystalline materials), the microstructures contain large fraction of grain boundaries. This subsequently introduces a variety of deformation mechanisms in the microstructure involving grain boundary-mediated processes such as grain boundary sliding and grain rotation, in addition to slip and twinning. A clear understanding of texture evolution in nano-crystalline materials, particularly at large strains, is a topic that remains largely unexplored.
The present work is an attempt to address the aforementioned issues pertaining to the evolution of deformation texture, namely, (i) the effect of SFE and (ii) the effect of grain size, in FCC metals and
alloys. Nickel-cobalt
alloys are chosen as the model system for the present investigation. The addition of cobalt to nickel leads to a systematic reduction of SFE as a function of cobalt content. In this thesis, three
alloys of Ni-Co system have been considered, namely, nickel – 20 wt.% cobalt, nickel – 40 wt.% cobalt and nickel – 60 wt.% cobalt. For a comparison, pure nickel has also been subjected to similar study.
Chapter 1 of the thesis presents a detailed survey of literature pertaining to the evolution of rolling textures in FCC metals and
alloys, and chapter 2 includes the details of the experimental techniques and characterization procedures, which are commonly employed for the entire work.
Chapter 3 addresses the effect of stacking fault energy on the evolution of rolling texture. The materials subjected to study in this chapter are microcrystalline Ni-Co
alloys. The texture evolution in Ni-20Co is very similar to pure Ni, and a characteristic Cu-type rolling texture is observed. The evolution of texture in these materials is primarily attributed to the intense dislocation activity throughout the deformation stages. In Ni-40Co, a medium SFE material, the rolling texture was predominantly Cu-type up to a strain of ε = 3 (95% thickness reduction). However, beyond this strain level, namely at ε = 4 (98%), the texture gets transformed to Bs-type with orientations maxima predominantly close to Goss ({110} <001>) position. Simultaneously, the Cu component which was dominant until 95% reduction has…
Advisors/Committee Members: Suwas, Satyam (advisor).
Subjects/Keywords: Microcrystalline Nickel-Cobalt Alloys; Nanocrystalline Nickel-Cobalt Alloys; Face Centered Cubic (FCC) Metals and Alloys; Nanocrystalline Nickel Alloys; Microcrystalline Nickel Alloys; Microcrystalline Alloys; Polycrystalline Metals; Stacking Fault Energy Alloys; Crystalline Texture; Nanocrystalline Alloys; Rolling Texture, Metals and Alloys; Deformation Texture; Rolled Polycrystalline Nickel Cobalt Alloys; Materials Science
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APA (6th Edition):
Radhakrishnan, M. (2017). Role Of Stacking Fault Energy On Texture Evolution In Micro- And Nano-Crystalline Nickel-Cobalt Alloys. (Doctoral Dissertation). Indian Institute of Science. Retrieved from http://etd.iisc.ac.in/handle/2005/2623
Chicago Manual of Style (16th Edition):
Radhakrishnan, Madhavan. “Role Of Stacking Fault Energy On Texture Evolution In Micro- And Nano-Crystalline Nickel-Cobalt Alloys.” 2017. Doctoral Dissertation, Indian Institute of Science. Accessed April 11, 2021.
http://etd.iisc.ac.in/handle/2005/2623.
MLA Handbook (7th Edition):
Radhakrishnan, Madhavan. “Role Of Stacking Fault Energy On Texture Evolution In Micro- And Nano-Crystalline Nickel-Cobalt Alloys.” 2017. Web. 11 Apr 2021.
Vancouver:
Radhakrishnan M. Role Of Stacking Fault Energy On Texture Evolution In Micro- And Nano-Crystalline Nickel-Cobalt Alloys. [Internet] [Doctoral dissertation]. Indian Institute of Science; 2017. [cited 2021 Apr 11].
Available from: http://etd.iisc.ac.in/handle/2005/2623.
Council of Science Editors:
Radhakrishnan M. Role Of Stacking Fault Energy On Texture Evolution In Micro- And Nano-Crystalline Nickel-Cobalt Alloys. [Doctoral Dissertation]. Indian Institute of Science; 2017. Available from: http://etd.iisc.ac.in/handle/2005/2623
Indian Institute of Science
28.
Narayanan, P Ramesh.
A Study Of Crystallographic Texture, Residual Stresses And Mechanical Property Anisotropy In Aluminium Alloys For Space Applications.
Degree: PhD, Faculty of Engineering, 2013, Indian Institute of Science
URL: http://etd.iisc.ac.in/handle/2005/1999
► Aluminium alloys, which are the most widely used materials in the aircraft and aerospace industries, find their applications due to high strength–to-density ratio, resistance to…
(more)
▼ Aluminium
alloys, which are the most widely used materials in the aircraft and aerospace industries, find their applications due to high strength–to-density ratio, resistance to catastrophic fracture, high degree of toughness, fabricability including good weldability and availability. High strength aluminum
alloys are used in different forms like sheets, forgings and extruded rods, welded and machined components in the aerospace industry. One major application of the aluminium
alloys in the space sector is in the launch vehicle and satellite sub-systems. The Indian Space Research Organization has met major challenges of indigenization of suitable aluminium
alloys, for example, Al-Cu
alloys (like AA2219) and Al–Zn-Mg
alloys (like AA7075 and AFNOR 7020).
Many failures of the metallic sub-systems made of different grades of aluminum
alloys have confirmed that high levels of residual stresses and unacceptable microstructures have played a role. Crystallographic texture in these materials has a very significant role to play in the performance of these materials in service. The anisotropy in the mechanical properties caused by crystallographic texture would add to the woes of the existing problems of residual stresses and directionality in the microstructure. In this context, a detailed study of crystallographic texture and residual stresses of high strength aluminium
alloys is mandatory. It is also important to study the influence of texture on the anisotropy in mechanical properties. The present research programme aims at addressing some of these aspects.
The entire work has been divided in three major sections, namely macro and micro texture analysis, non-destructive measurement of residual stresses using X-ray Diffraction (XRD) and the Ultrasonic Testing (UST) and the study of anisotropy in the mechanical properties arising due to the above two factors. The thesis composition is as follows.
In Chapter I, a detailed survey of the literature has been presented wherein basic physical metallurgy for different aluminum
alloys of interest has been given. Thereafter, details of texture measurement by the X-ray diffraction and Electron Back Scatter Diffraction (EBSD) are presented. This is followed by a detailed review on the texture studies carried out in aluminium
alloys under various conditions. Literature review on the two non-destructive methods, namely the X-ray diffraction and ultrasonic method has been carried out in detail. In order to account for microstructural changes, Differential Scanning Calorimetry (DSC) was carried out. Recent work on the mechanical property anisotropy arising due to high degree of mechanical working in aluminium
alloys has been reviewed.
Chapter II includes the experimental details involved in the course of the present investigation. The procedural details of cold rolling and associated microstructural changes are given in this chapter. This is followed by the texture measurement methods. Experimental details of the bulk texture measurement using the X-ray diffraction and micro texture…
Advisors/Committee Members: Ranganathan, S (advisor), Suwas, Satyam (advisor).
Subjects/Keywords: Aluminium Alloys; Crystallography; Aluminium Alloys - Mechanical Properties; Aluminium Alloys - Residual Stresses; Aluminium Alloys - Texture; Aluminium Alloys - Physical Metallurgy; Alluminium Alloys - Space Applications; Aluminium Alloys - Crystallographic Structure; AA2219 Al Alloy; AFNOR7020 Al Alloy; Al-Zn-Mg Alloys; Al Alloys; AA2219 Aluminium Alloys; Metallurgy
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APA (6th Edition):
Narayanan, P. R. (2013). A Study Of Crystallographic Texture, Residual Stresses And Mechanical Property Anisotropy In Aluminium Alloys For Space Applications. (Doctoral Dissertation). Indian Institute of Science. Retrieved from http://etd.iisc.ac.in/handle/2005/1999
Chicago Manual of Style (16th Edition):
Narayanan, P Ramesh. “A Study Of Crystallographic Texture, Residual Stresses And Mechanical Property Anisotropy In Aluminium Alloys For Space Applications.” 2013. Doctoral Dissertation, Indian Institute of Science. Accessed April 11, 2021.
http://etd.iisc.ac.in/handle/2005/1999.
MLA Handbook (7th Edition):
Narayanan, P Ramesh. “A Study Of Crystallographic Texture, Residual Stresses And Mechanical Property Anisotropy In Aluminium Alloys For Space Applications.” 2013. Web. 11 Apr 2021.
Vancouver:
Narayanan PR. A Study Of Crystallographic Texture, Residual Stresses And Mechanical Property Anisotropy In Aluminium Alloys For Space Applications. [Internet] [Doctoral dissertation]. Indian Institute of Science; 2013. [cited 2021 Apr 11].
Available from: http://etd.iisc.ac.in/handle/2005/1999.
Council of Science Editors:
Narayanan PR. A Study Of Crystallographic Texture, Residual Stresses And Mechanical Property Anisotropy In Aluminium Alloys For Space Applications. [Doctoral Dissertation]. Indian Institute of Science; 2013. Available from: http://etd.iisc.ac.in/handle/2005/1999
Indian Institute of Science
29.
Mondol, Sukla.
Improving High Temperature Strength of 2219 Al Alloy by Minor Alloying Additions.
Degree: PhD, Faculty of Engineering, 2018, Indian Institute of Science
URL: http://etd.iisc.ac.in/handle/2005/3755
► Among Al alloys, 2219 Al alloy possesses highest strength at elevated temperatures. However, the application of this alloy is also restricted to a maximum temperature…
(more)
▼ Among Al
alloys, 2219 Al alloy possesses highest strength at elevated temperatures. However, the application of this alloy is also restricted to a maximum temperature of 150°C, above which, the strengthening precipitates coarsen rapidly resulting in a steep loss in strength. In the present investigation, an attempt has been made to improve the elevated as well as the room temperature properties of commercial 2219 alloy by the addition of small amounts of Sc & Mg, Sc & Zr, and Nb & Zr, and these are designated as 2219ScMg, 2219ScZr and 2219NbZr
alloys, respectively.
All the three
alloys were cast in the form of strips in a water cooled copper mould using suction casting technique with a cooling rate of 102 to 103 K/s. The as-cast strips of 2219ScMg
alloys were naturally aged and cold rolled by following three different routes (a) cold rolling, (b) homogenization and cold rolling and (c) hot rolling and cold rolling.
A significant improvement in strength has been achieved by all the three wrought processing routes with greater than 140 MPa increase in 0.2% proof stress at room temperature and greater than 110 MPa increase in 0.2% proof stress at 200°C as compared to 2219-T851 alloy having 0.2% proof stress of 345 MPa at room temperature and 205 MPa at 200°C. Hardness values, measured at room temperature after exposure at 200°C, remain stable up to 1000 h.
Microstructural analysis of 2219ScMg alloy reveals that Al3Sc or Al3(Sc,Zr) dispersoids form during casting and GP zones form on {100} and {111} plane during natural ageing. Subsequently, rolling introduces higher dislocation densities in the matrix. All these microstructural features contribute to the improvement of the room temperature strength of the alloy. On exposure at 200°C, GP zones transform to mainly θ′ and a few Ω precipitates. A finer, homogeneous distribution of θ′ and Ωprecipitates yields higher strength. Sc and Mg atoms are segregated at the θ′/matrix interface, which gives rise to slower growth kinetics of θ′ precipitates. As a result, the alloy exhibits better thermal stability at 200°C. For 2219ScZr and 2219NbZr
alloys, the processing of the cast strip involves a two stage ageing procedure. This includes first stage ageing at 375°C for 2219ScZr alloy and at 400°C for 2219NbZr alloy. This is followed by solution treatment at 535°C for 30 minutes and second stage ageing at 200°C for both the
alloys.
For 2219ScZr alloy, tensile tests performed at room temperature, 200°C and 250°C show 0.2% proof stress of 456 ± 22 MPa, 295 ± 20 MPa and 227 ± 2 MPa respectively. The alloy is found to be thermally stable at 200°C. It is found that the addition of Sc and Zr results in the formation of Al3(Sc,Zr) precipitates during ageing at 375°C. These precipitates are fully coherent with the matrix and have a significant precipitation hardening effect. They also stimulate the nucleation of θ′′ and θ′precipitates during ageing at 200°C making them finer, homogeneously distributed and thermally stable. Therefore, the strength of the alloy at ambient and elevated…
Advisors/Committee Members: Kumar, Subodh (advisor), Chattopadhyay, Kamanio (advisor).
Subjects/Keywords: Alluminium Alloys; 2219 Alluminium Alloys; High Temperature Alloys; Scandium Magnesium Alloys; Scandium Zirconium Alloys; Niobium Zirconium Alloys; Alloying Elements; 2219ScMg Alloy; 2219ScZr Alloy; 2219NbZr Alloy; 2219 Al Alloy; Materials Engineering
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APA ·
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APA (6th Edition):
Mondol, S. (2018). Improving High Temperature Strength of 2219 Al Alloy by Minor Alloying Additions. (Doctoral Dissertation). Indian Institute of Science. Retrieved from http://etd.iisc.ac.in/handle/2005/3755
Chicago Manual of Style (16th Edition):
Mondol, Sukla. “Improving High Temperature Strength of 2219 Al Alloy by Minor Alloying Additions.” 2018. Doctoral Dissertation, Indian Institute of Science. Accessed April 11, 2021.
http://etd.iisc.ac.in/handle/2005/3755.
MLA Handbook (7th Edition):
Mondol, Sukla. “Improving High Temperature Strength of 2219 Al Alloy by Minor Alloying Additions.” 2018. Web. 11 Apr 2021.
Vancouver:
Mondol S. Improving High Temperature Strength of 2219 Al Alloy by Minor Alloying Additions. [Internet] [Doctoral dissertation]. Indian Institute of Science; 2018. [cited 2021 Apr 11].
Available from: http://etd.iisc.ac.in/handle/2005/3755.
Council of Science Editors:
Mondol S. Improving High Temperature Strength of 2219 Al Alloy by Minor Alloying Additions. [Doctoral Dissertation]. Indian Institute of Science; 2018. Available from: http://etd.iisc.ac.in/handle/2005/3755
30.
Johnsen, John LeRoy.
An investigation of selected properties of as-cast, V-Ti-Fe alloys.
Degree: PhD, 1985, Oregon Health Sciences University
URL: doi:10.6083/M4862DC1
;
http://digitalcommons.ohsu.edu/etd/83
Subjects/Keywords: Vanadium alloys; Titanium alloys; Iron alloys
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APA (6th Edition):
Johnsen, J. L. (1985). An investigation of selected properties of as-cast, V-Ti-Fe alloys. (Doctoral Dissertation). Oregon Health Sciences University. Retrieved from doi:10.6083/M4862DC1 ; http://digitalcommons.ohsu.edu/etd/83
Chicago Manual of Style (16th Edition):
Johnsen, John LeRoy. “An investigation of selected properties of as-cast, V-Ti-Fe alloys.” 1985. Doctoral Dissertation, Oregon Health Sciences University. Accessed April 11, 2021.
doi:10.6083/M4862DC1 ; http://digitalcommons.ohsu.edu/etd/83.
MLA Handbook (7th Edition):
Johnsen, John LeRoy. “An investigation of selected properties of as-cast, V-Ti-Fe alloys.” 1985. Web. 11 Apr 2021.
Vancouver:
Johnsen JL. An investigation of selected properties of as-cast, V-Ti-Fe alloys. [Internet] [Doctoral dissertation]. Oregon Health Sciences University; 1985. [cited 2021 Apr 11].
Available from: doi:10.6083/M4862DC1 ; http://digitalcommons.ohsu.edu/etd/83.
Council of Science Editors:
Johnsen JL. An investigation of selected properties of as-cast, V-Ti-Fe alloys. [Doctoral Dissertation]. Oregon Health Sciences University; 1985. Available from: doi:10.6083/M4862DC1 ; http://digitalcommons.ohsu.edu/etd/83
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Open Access Theses and Dissertations