Dissertations / Theses: 'Aluminum alloys'

1

Nafisi, Shahrooz. "Effects of grain refining and modification on the microstructural evolution of semi-solid 356 alloy = Effets de l'affinage des grains et de la modification sur l'évolution microstructurale de l'alliage 356 semi-solide /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2006. http://theses.uqac.ca.

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2

Ergin, Guvenc. "Étude de la mouillabilité des particules granulaires par les alliages d'aluminium durant la filtration d'aluminium /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2006. http://theses.uqac.ca.

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Thèse (D.Eng.) -- Université du Québec à Chicoutimi, 2006.
La p. de t. porte en outre: Thèse présentée à l'Université du Québec à Chicoutimi pour l'obtention du doctorat en ingénierie. CaQCU Bibliogr.: f. 130-147. Document électronique également accessible en format PDF. CaQCU

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3

Saoudi, Abdelhamid. "Prédiction de la rupture par fatigue dans les pièces automobiles en alliages aluminium /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2008. http://theses.uqac.ca.

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Thèse (D.Eng.) -- Université du Québec à Chicoutimi, 2008.
La p. de t. porte en outre: Doctorat en ingénierie, thèse pour l'obtention du titre de Philosophiae Doctor en ingénierie. CaQQUQ Comprend des réf. bibliogr. (f. 174-178). Publié aussi en version électronique. CaQQUQ

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4

Mohamed, Adel. "Effet des additifs sur la microstructure et les propriétés mécaniques des alliages d'aluminium-silicium /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2008. http://theses.uqac.ca.

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Thèse (D.Eng..) -- Université du Québec à Chicoutimi, 2008.
La p. de t. porte en outre: Thèse présenté[e] à l'Université du Québec à Chicoutimi comme exigence partielle du doctorat en ingénierie. CaQQUQ Comprend des réf. bibliogr. (f. [292]-314). Publié aussi en version électronique. CaQQUQ

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5

El, Sebaie Ossama. "L'effet de l'addition du "mischmetal", du taux de refroidissement et du traitement thermique sur la microstructure et la dureté des alliages Al-Si de type 319, 356, et 413 = Effect of mischmetal, cooling rate and heat treatment on the microstructure and hardness of 319, 3456, and 413 Al-Si alloys /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2006. http://theses.uqac.ca.

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6

Golbahar, Behnam. "Effect of grain refiner-modifier interaction on the performance of A356.2 alloy." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2008. http://theses.uqac.ca.

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Thèse (M.Eng.) -- Université du Québec à Chicoutimi, 2008.
La p. de t. porte en outre: Mémoire présenté à l'Université du Québec à Chicoutimi comme exigence partielle de la maîtrise en ingénierie. CaQQUQ Comprend des réf. bibliogr. (f. 149-155). Publié aussi en version électronique. CaQQUQ

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7

Yang, Deyu. "Rôle d'addition de magnésium sur l'occurence de la fonte naissante dans les alliages expérimentaux et commerciaux Al-Si-Cu et son influence sur la microstructure et les propriétés de traction de l'alliage = Role of magnesium addition on the occurence of incipient melting in experimental and commercial Al-Si-Cu alloys and its influence on the alloy microstructure and tensile properties /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2006. http://theses.uqac.ca.

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8

Blanchette, Hugues. "Développement d'un système de contrôle de qualité pour les lopins d'aluminium semi-solide[s] obtenus avec le procédé SEED /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2006. http://theses.uqac.ca.

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9

Lebeau, Thomas. "Wetting of alumina-based ceramics by aluminum alloys." Thesis, McGill University, 1993. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=68039.

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During the last 20 years, ceramic fiber reinforced metal matrix composites, referred to as MMCs, have provided a relatively new way of strengthening metals. High specific modulus and a good fatigue resistance in dynamic loading conditions or for high temperature applications make these composites very attractive for replacing classic alloys. The first requirement for the fabrication of MMCs, especially by processes involving liquid metals, is a certain degree of wetting of fibers by the liquid metal which will permit a good bonding between the two phases.
The conventional experimental approach to wettability consists of measuring the contact angle of a drop of the liquid metal resting on flat substrate of the ceramic reinforcement materials.
This work deals with the fabrication of eutectic $ rm ZrO sb2/Al sb2O sb3 (ZA), ZrO sb2/Al sb2O sb3/TiO sb2$ (ZAT), and $ rm ZrO sb2/Al sb2O sb3/SiO sb2$ (ZAS) ceramic substrates and the study of their wetting behavior by different classes of Al alloys. Wetting experiments were performed under high vacuum or under ultra high purity Ar atmosphere. Four major variables were tested to study the wetting behavior of the different ceramic/metal systems. Variables include holding time, melt temperature, alloy and ceramic compositions.
Ceramic materials were sintered under vacuum at temperatures ranging from 1500$ sp circ$C to 1790$ sp circ$C for 2.5 hours, and achieved over 96% of the theoretical density. An experimental set-up was designed to measure in-situ contact angles using the sessile drop method. For any ceramic substrate, a temperature over 950$ sp circ$C was necessary to observe an equilibrium wetting angle less than 90$ sp circ$ with pure Al; by alloying the aluminum, wetting could be observed at lower temperatures ($ theta$ = 76-86$ sp circ$ at 900$ sp circ$C for Al-10wt%Si, $ theta sim72 sp circ$ at 850$ sp circ$C for Al-2.4wt%Mg). Finally, ZAS specimens reacted with molten Al alloys over 900$ sp circ$C to produce Zr-Al based intermetallics at the metal/ceramic interface.

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10

Ammar, Hany. "Effet des imperfections de la coulée sur les propriétés en fatigue des alliages de fonderie aluminium silicium = Effect of casting imperfections on the fatigue properties of aluminum-silicon casting alloys /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2006. http://theses.uqac.ca.

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11

Gustafsson, Sofia. "Corrosion properties of aluminium alloys and surface treated alloys in tap water." Thesis, Uppsala universitet, Institutionen för materialkemi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-157527.

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The aim of this thesis is to obtain a basic knowledge of the factors that affect corrosion of aluminium in tap water for different kinds of applications like water pipes for tap water, solar systems, HVAC&R-applications (like fan coil units on chillers) and heat sinks for electronic or industrial applications. Open systems are used in some applications and closed systems in others. There is a clear difference in the corrosion behaviour of these two systems. The main reasons for this difference are that the content of oxygen differs between the two systems and also that inhibitors can be used in closed systems to hinder corrosion. In this thesis focus will be on corrosion in open systems. The corrosion properties in tap water for different alloys of aluminium and different surface treatments have been examined. The influences on corrosion of the oxygen content in water and the iron content in aluminium alloys have been investigated. The corrosion properties of an aluminium alloy in deionised water have also been examined.

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12

Park, Sungbae. "Rheocasting of aluminium alloys." Thesis, University of Oxford, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.670041.

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13

Fransson, Christoffer. "Accelerated aging of aluminum alloys." Thesis, Karlstad University, Karlstad University, Karlstad University, Karlstad University, 2009. http://urn.kb.se/resolve?urn=urn:nbn:se:kau:diva-5041.

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In order to determine storage life for aluminum alloys it is essential to have a good knowledge on the accelerated aging behavior and the mechanical properties that are affected. The selected aluminum alloys are AA2017, AA6082, AA7075 and the study has been focused on their impact toughness and hardness relation to aging beyond peak conditions. To be able to plot the mechanical properties versus aging time and temperature, Differential Scanning Calorimetric runs have been the key to obtain supporting activation energies for a specific transformation. The activation energies have been calculated according to the Kissinger method, plotted in Matlab. Arrhenius correlation has also been applied to predict the natural aging time for long time storage in 30 degrees Celsius. It could be concluded that the results from the mechanical test series show that the constructed Arrhenius 3D method did not meet the expectations to extrapolate constant activation energies down to storage life condition. Scanning electron microscopy together with light optical microscopy analyses show how important it is to apply notches in proper test specimen directions and how precipitates are grown, as it will affect impact toughness and hardness.

An ending discussion is held to explain how mechanical testing progressed and how other external issues affected the master thesis operations.

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14

Durbin, Tracie L. "Modeling Dissolution in Aluminum Alloys." Diss., Georgia Institute of Technology, 2005. http://hdl.handle.net/1853/6873.

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Aluminum and its alloys are used in many aspects of modern life, from soda cans and household foil to the automobiles and aircraft in which we travel. Aluminum alloy systems are characterized by good workability that enables these alloys to be economically rolled, extruded, or forged into useful shapes. Mechanical properties such as strength are altered significantly with cold working, annealing, precipitation-hardening, and/or heat-treatments. Heat-treatable aluminum alloys contain one or more soluble constituents such as copper, lithium, magnesium, silicon and zinc that individually, or with other elements, can form phases that strengthen the alloy. Microstructure development is highly dependent on all of the processing steps the alloy experiences. Ultimately, the macroscopic properties of the alloy depend strongly on the microstructure. Therefore, a quantitative understanding of the microstructural changes that occur during thermal and mechanical processing is fundamental to predicting alloy properties. In particular, the microstructure becomes more homogeneous and secondary phases are dissolved during thermal treatments. Robust physical models for the kinetics of particle dissolution are necessary to predict the most efficient thermal treatment. A general dissolution model for multi-component alloys has been developed using the front-tracking method to study the dissolution of precipitates in an aluminum alloy matrix. This technique is applicable to any alloy system, provided thermodynamic and diffusion data are available. Treatment of the precipitate interface is explored using two techniques: the immersed-boundary method and a new technique, termed here the sharp-interface method. The sharp-interface technique is based on a variation of the ghost fluid method and eliminates the need for corrective source terms in the characteristic equations. In addition, the sharp-interface method is shown to predict the dissolution behavior of precipitates in aluminum alloys when compared with published experimental results. The influence of inter-particle spacing is examined and shown to have a significant effect on dissolution kinetics. Finally, the impact of multiple particles of various sizes interacting in an aluminum matrix is investigated. It is shown that smaller particles dissolve faster, as expected, but influence the dissolution of larger particles through soft-impingement, even after the smaller particles have disappeared.

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15

Gammage, Justin Wilkinson D. S. "Damage in heterogeneous aluminum alloys /." *McMaster only, 2002.

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16

Khajeh, Ehsan. "Permeability of hypoeutectic aluminum alloys." Thesis, University of British Columbia, 2011. http://hdl.handle.net/2429/36586.

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The interdendritic permeability is a critical parameter that defines the feedability of the mushy zone during solidification. In this study, a theoretical expression to describe the evolution of permeability throughout the complete solidification range (from dendritic to dendritic/eutectic) of hypoeutectic aluminum alloys has been derived, verified and validated through physical and numerical modeling. The permeability of the primary, equiaxed, dendritic phase has been characterized using geometries obtained by X-ray microtomographic analysis of Al-4.5wt%Cu alloy samples quenched at different temperatures after the start of solidification. The permeability during equiaxed eutectic solidification was characterized on simulated dendritic/eutectic microstructures predicted using a Cellular Automaton technique. For both the dendritic and dendritic/eutectic structures, the permeability was characterized i) physically using large-scale analogues of the characterized microstructures and ii) numerically by predicting the flow through the simulated microstructures. The microstructural parameters were then linked to more practical parameters available in solidification models through i) developing an inverse analysis technique to characterize eutectic solidification and ii) development of a geometric model for dendritic solidification. The permeability values determined through physical and numerical modeling are in good agreement with each other and are consistent with the mathematical expression. The proposed permeability expression is valid over the complete solidification range and for a wide range of compositions. The expression reduces to the conventional Carman-Kozeny expression during dendritic solidification and/or dendritic/eutectic solidification with low density of eutectic grains. However, it deviates from the conventional Carman-Kozeny expression as the density of eutectic grains increases.

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17

Pletcher, Ben A. "Kinetics of aluminum lithium alloys." [Gainesville, Fla.] : University of Florida, 2009. http://purl.fcla.edu/fcla/etd/UFE0024666.

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18

Shirandasht, Jamshid. "Évaluation de la technique LiMCA II pour la mesure d'inclusions dans l'aluminium pur et l'alliage binaire Al-6%Si : rôle de la température de coulée /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2005. http://theses.uqac.ca.

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19

Rivet, Frederic C. "Hydrogen embrittlement of Aluminum-Lithium alloys." Thesis, Virginia Tech, 1990. http://hdl.handle.net/10919/41599.

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The objective of this work is to study the effects of dissolved hydrogen on the mechanical properties of aluminum-lithium alloys: 2090, 2091, and Weldalite 049, and to compare with the effects on aluminum-copper 2219 alloy. Prior to mechanical testing, aging studies were performed for 2090 and 2219 using microhardness Vickers to determine the peak aged condition required by NASA. The Charpy tests are part of this study designed to investigate the effects of temperature and notch orientation on fracture behavior. Disk rupture tests were used with various gases (hydrogen and nitrogen) and three strain rates (increment of 50 psi every 20, 200 and 300 seconds) and two temperatures (room and liquid nitrogen temperatures) to determine the effects of hydrogen on the sample during the tests. Some independent studies on the corrosion behavior and electrochemical hydrogen charging of 2219 and 2090 were also performed. An effect of double peak aged condition was found for both 2219 and 2090 alloys. Prior to mechanical testing, the 2090 received in the T3 or W51 conditions was chosen to be aged in an air furnace at 170°C for 16 hours. The Charpy studies showed a higher propagation energy needed for the T-S and L-S orientations than for the L-T and T-L orientations, due in large part to the extensive delamination propagation of the fracture. The disk rupture tests showed a important decrease of the fracture to failure on the 2090 and 2091 due to hydrogen while no important variations were seen for the 2219 and the weldalite 049 alloys. No effect of hydrogen were found, with the disk rupture test, at cryogenic temperature and for all alloys. The corrosion behavior of 2219, as well as 2090, showed development of pits under neutral and acidic environments while general corrosion was obtained with basic environment. Two solutions were found to charge the samples in hydrogen: a potentiostatic test for 5 hours at -3V, and a galvanostatic test for 20 hours at -500μA, both performed in a 0.04 N HCl plus As₂O₃ environment.
Master of Science

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20

Gagnon, Dominique. "Effets des paramètres métallurgiques sur la microstructure, la macrostructure et la performance des alliages 319, 356 et 413 /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2005. http://theses.uqac.ca.

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21

Harsacky, Frank J. Jr. "Processing studies of aluminum-magnesium and aluminum-copper-lithium alloys." Thesis, Monterey, California: Naval Postgraduate School, 1990. http://hdl.handle.net/10945/34850.

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Approved for public release; distribution is unlimited.
Investigation into the effect on superplastic behavior of two aluminum alloys produced by variations of thermomechanical processing parameters was conducted. The alloys in this study are Al-10Mg-0.1Zr (weight percent) and 2090, which is Al-2.56Cu-2.03Li-0.12Zr (weight percent). Determination of the existence of an optimum balance between deformation and recovery for the Al-10Mg-0.1Zr alloy was accomplished by extending the annealing interval to 60 minutes during warm rolling at 300 C. The optimum balance is a 30 minute annealing interval between rolling passes. Processing of Al-10Mg-0.1Zr with a rolling temperature lower than the annealing temperature produced ductilities which are less than those obtained by utilization of the optimum process. The extension of annealing intervals in the processing of 2090 resulted in increased superplastic response when compared with results obtained employing shorter annealing intervals. By application of a two-temperature process which incorporates rolling at a lower temperature than the annealing temperature, the determination has been made that enhanced ductility results however, the annealing interval of 14 minutes should be extended.

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22

Matulich, Ryan Douglas. "Post-fire Mechanical Properties of Aluminum Alloys and Aluminum Welds." Thesis, Virginia Tech, 2011. http://hdl.handle.net/10919/32727.

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The focus of this research was to quantify the post-fire mechanical properties of 5083-H116 and 6082-T6 aluminum alloys. Post-fire exposure is considered heating the material to a particular temperature then cooling the material back to room temperature. The research included evaluating parent materials as well as welded samples. Post-fire mechanical properties of parent materials were evaluated at temperatures ranging from ambient to 500oC with isothermal and transient heating. Changes in material properties were evaluated through static tensile tests and hardness testing on cooled samples. Using this data, an assessment was performed to investigate the relationship between hardness and mechanical properties. For the alloys evaluated, empirical relationships were found between Vickers hardness and post-fire strength. Testing was also performed on butt welded samples of 6082-T6 exposed isothermally to temperatures ranging from ambient to 500oC. Vickers hardness profiles were measured across a sample to quantify the hardness of the weld, heat affected zone, and parent material. This was performed at room temperature and following different heat exposures. Static tensile tests were used to evaluate the effect of reheating on the welded samples. Post-fire strength of welded samples was strongly affected by weld geometry. Parent material hardness varied with reheating while weld hardness remained constant. At select temperatures, this resulted in the weld having a higher Vickers hardness than the parent material. Despite this tensile failure always occurred within the weld.
Master of Science

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23

Conte-Matos, Augusto. "The role of alloy composition and cooling rate from the melt on the dispersoid distribution in AA 6013." Diss., Georgia Institute of Technology, 1996. http://hdl.handle.net/1853/20208.

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24

Paramatmuni, Rohit K. "Solidification cracking resistance of high strength aluminum alloys." Morgantown, W. Va. : [West Virginia University Libraries], 2003. http://etd.wvu.edu/templates/showETD.cfm?recnum=2775.

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Thesis (M.S.)--West Virginia University, 2003.
Title from document title page. Document formatted into pages; contains xi, 71 p. : ill. Vita. Includes abstract. Includes bibliographical references (p. 53-56).

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25

Tash, Mahmoud. "Effect [sic] des paramètres métallurgiques sur le comportement d'usinage des alliages 356 et 319 (étude de forage et de taraudage) /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2005. http://theses.uqac.ca.

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26

Sun, Ning. "Friction stir processing of aluminum alloys." Worcester, Mass. : Worcester Polytechnic Institute, 2009. http://www.wpi.edu/Pubs/ETD/Available/etd-050109-144331/.

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Last, Howard R. "Precipitation of dispersoids in aluminum alloys." Diss., Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/19895.

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Rofman, Oleg V. "Dynamic grain growth in aluminum alloys." Thesis, University of Manchester, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.489016.

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ITHARAJU, RAJESWARI R. "FRICTION STIR PROCESSING OF ALUMINUM ALLOYS." UKnowledge, 2004. http://uknowledge.uky.edu/gradschool_theses/322.

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Friction stir processing (FSP) is one of the new and promising thermomechanical processing techniques that alters the microstructural and mechanical properties of the material in single pass to achieve maximum performance with low production cost in less time using a simple and inexpensive tool. Preliminary studies of different FS processed alloys report the processed zone to contain fine grained, homogeneous and equiaxed microstructure. Several studies have been conducted to optimize the process and relate various process parameters like rotational and translational speeds to resulting microstructure. But there is only a little data reported on the effect of the process parameters on the forces generated during processing, and the resulting microstructure of aluminum alloys especially AA5052 which is a potential superplastic alloy. In the present work, sheets of aluminum alloys were friction stir processed under various combinations of rotational and translational speeds. The processing forces were measured during the process and the resulting microstructure was analyzed using TEM. The results indicate that the processing forces and the microstructure evolved during FSP are sensitive to the rotational and translational speed. It is observed that the forces generated increase with the increasing rotational speed. The grain refinement was observed to vary directly with rotational speed and inversely with the translational speed. Also these forces generated were proportional to the grain refinement i.e., greater refinement of grains occurred at lower forces. Thus the choice of process parameters especially the rotational speed has a significant effect on the control and optimization of the process.

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30

Sunseri, Erin Hannah. "Dendrite orientation in aluminum magnesium alloys." [Ames, Iowa : Iowa State University], 2009.

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Sun, Ning. "Friction Stir Processing of Aluminum Alloys." Digital WPI, 2012. https://digitalcommons.wpi.edu/etd-dissertations/552.

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Friction stir processing (FSP) has been developed based on the basic principles of friction stir welding (FSW), a solid-state joining process originally developed for aluminum alloys. What is attractive about FSP is that it can be incorporated in the overall manufacturing cycle as a post-processing step during the machining operation to provide localized modification and control of microstructures in near-surface layers of metallic components. FSP has emerged as an important post-processing technique, and has been identified as a process that may have a high impact, and perhaps is a disruptive manufacturing process. In this study, FSP has been applied to Al cast alloy A206, which is a high strength, widely used cast alloy in the manufacturing industry. Motivations behind this work are to (1) investigate the feasibility of FSP on manipulating the cast microstructure and strengthening the material, and (2) to explore the viability of FSP to produce a localized particle reinforced zone in cast A206 aluminum components. The thesis will show that we have optimized FSP for processing of Al alloys to locally manipulate the cast microstructure, eliminate casting defects, and attain grain refinement and second phase homogenization. We have established the mechanism leading to the microstructure evolution and have evaluated the resultant mechanical properties, i.e. hardness, tensile property and fatigue properties. We have also synthesized a localized composite material in the A206 work piece with three different reinforcement materials via FSP. These results will be presented and discussed.

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32

Eaton, James Allen. "Effect of temperature and percent cold work on the mechanical properties of aluminum alloy 3104." Master's thesis, This resource online, 1992. http://scholar.lib.vt.edu/theses/available/etd-03302010-020243/.

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33

Gagné, Stéphane. "Effets de l'augmentation de la teneur en titane sur l'affinage des grains de l'alliage A356.2 /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2005. http://theses.uqac.ca.

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Liu, Li. "Évaluation de la propreté des alliages d'aluminium de fonderie A356.2 et C357 à l'aide de la technique PoDFA /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 1997. http://theses.uqac.ca.

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35

Bhattacharya, Victoria. "Study Of Friction And Wear Behaviour Of Nano-Embedded Aluminium Alloys." Thesis, Indian Institute of Science, 2000. https://etd.iisc.ac.in/handle/2005/190.

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In general, the bearing alloys have two types of microstructure i.e., either a soft matrix with discrete hard particles or a continuous matrix of the harder metal with small amount of the softer metal finely dispersed in it. The aluminium and copper based bearing alloys which are widely studied fall in the second category. However, the bearing materials which have been studied have micron sized dispersoids. In recent times, it is possible to produce nanoscale dispersoids in a hard matrix by the novel processing route of rapid solidification. This offers an opportunity to study the small length scale effect on tribological processes. In this thesis, we deal with aluminium alloys where nanoscaled dispersions of lead, bismuth and indium are produced by rapid solidification processing. Chapter 1 of the thesis is an introduction, followed by Chapter 2, which reviews the literature on nanomaterials. Special attention is given to the monotectic system, followed by a brief description on friction and wear of materials which is necessary for our present investigation. The details of experimental and characterisation techniques are given in Chapter 3. In Chapter 4, we present a brief study of white metal bearings (babbit). Tin-based babbit of composition, Sn-6wt% Cu-llwt% Sb was studied. The study of babbit was mainly carried out with the idea that it could serve as a benchmark for subsequent studies in aluminium alloys, in terms of tribological properties. In particular, we have carried out a detailed electron microscopic investigation on the phases present in the bearing alloy. The friction and wear behaviour of this material confirms the proper calibration of our setup for wear studies. This is followed by a detailed study on the synthesis, microstructure and tribological behaviour of nanodispersed aluminium alloys, Al-6wt% Pb and Al-10wt% Pb in Chapter 5. For comparison, we have also studied melt-spun aluminium without dispersoids. Detailed electron microscopic characterisation indicates that lead has a cube on cube orientation relationship with the aluminium matrix, and the particles exhibit a lognormal distribution with the mode of the particle size distribution being 15 nm. The pin on disc results suggest a distinct lowering of coefficient of friction corresponding to pure aluminium (μ= 0.40) and as cast aluminium-lead alloys (μ= 0.41). Detailed SEM studies indicate a tribolayer consisting primarily of Al, Pb and Fe. The later comes from the counterface material. Our results clearly indicate that at an early stage, little or no oxidation takes place at the sliding interface. TEM observations indicate significant deformation of lead particles in the sub-surface region. The observations suggest spreading of the lead, which acts as a lubricating layer. Wear behaviour is primarily adhesive and follows Archard's wear law. However, the rate of wear is less than that reported by other investigators on micronsized lead dispersions in aluminium. In Chapter 6, we present the results for alloys dispersed with nanosized indium and bismuth. We show that indium particles on melt-spinning exhibit both cubic and tetragonal crystal structure. The indium particles are coarser (with a mode of 25 nm) than the lead and bismuth particles (which have mode of 15nm). The bismuth containing alloys have a lower wear rate and coefficient of friction compared to lead and indium alloys. However, both indium and bismuth particles do not follow Archard's wear law and the wear vs load graph shows a non-linear behaviour. The results are discussed in terms of known mechanisms of the coefficient of friction and wear. Chapter 7 gives the salient conclusions while in Chapter 8 we discuss some of the unanswered questions and the potential for future work in this field.

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Bhattacharya, Victoria. "Study Of Friction And Wear Behaviour Of Nano-Embedded Aluminium Alloys." Thesis, Indian Institute of Science, 2000. http://hdl.handle.net/2005/190.

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In general, the bearing alloys have two types of microstructure i.e., either a soft matrix with discrete hard particles or a continuous matrix of the harder metal with small amount of the softer metal finely dispersed in it. The aluminium and copper based bearing alloys which are widely studied fall in the second category. However, the bearing materials which have been studied have micron sized dispersoids. In recent times, it is possible to produce nanoscale dispersoids in a hard matrix by the novel processing route of rapid solidification. This offers an opportunity to study the small length scale effect on tribological processes. In this thesis, we deal with aluminium alloys where nanoscaled dispersions of lead, bismuth and indium are produced by rapid solidification processing. Chapter 1 of the thesis is an introduction, followed by Chapter 2, which reviews the literature on nanomaterials. Special attention is given to the monotectic system, followed by a brief description on friction and wear of materials which is necessary for our present investigation. The details of experimental and characterisation techniques are given in Chapter 3. In Chapter 4, we present a brief study of white metal bearings (babbit). Tin-based babbit of composition, Sn-6wt% Cu-llwt% Sb was studied. The study of babbit was mainly carried out with the idea that it could serve as a benchmark for subsequent studies in aluminium alloys, in terms of tribological properties. In particular, we have carried out a detailed electron microscopic investigation on the phases present in the bearing alloy. The friction and wear behaviour of this material confirms the proper calibration of our setup for wear studies. This is followed by a detailed study on the synthesis, microstructure and tribological behaviour of nanodispersed aluminium alloys, Al-6wt% Pb and Al-10wt% Pb in Chapter 5. For comparison, we have also studied melt-spun aluminium without dispersoids. Detailed electron microscopic characterisation indicates that lead has a cube on cube orientation relationship with the aluminium matrix, and the particles exhibit a lognormal distribution with the mode of the particle size distribution being 15 nm. The pin on disc results suggest a distinct lowering of coefficient of friction corresponding to pure aluminium (μ= 0.40) and as cast aluminium-lead alloys (μ= 0.41). Detailed SEM studies indicate a tribolayer consisting primarily of Al, Pb and Fe. The later comes from the counterface material. Our results clearly indicate that at an early stage, little or no oxidation takes place at the sliding interface. TEM observations indicate significant deformation of lead particles in the sub-surface region. The observations suggest spreading of the lead, which acts as a lubricating layer. Wear behaviour is primarily adhesive and follows Archard's wear law. However, the rate of wear is less than that reported by other investigators on micronsized lead dispersions in aluminium. In Chapter 6, we present the results for alloys dispersed with nanosized indium and bismuth. We show that indium particles on melt-spinning exhibit both cubic and tetragonal crystal structure. The indium particles are coarser (with a mode of 25 nm) than the lead and bismuth particles (which have mode of 15nm). The bismuth containing alloys have a lower wear rate and coefficient of friction compared to lead and indium alloys. However, both indium and bismuth particles do not follow Archard's wear law and the wear vs load graph shows a non-linear behaviour. The results are discussed in terms of known mechanisms of the coefficient of friction and wear. Chapter 7 gives the salient conclusions while in Chapter 8 we discuss some of the unanswered questions and the potential for future work in this field.

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37

Roy, Normand. "Étude paramétrique de l'évolution de la porosité dans le système Al-9%Si-3%Cu /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 1994. http://theses.uqac.ca.

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38

Chen, Hu. "L'effet du taux de refroidissement, modification au strontium, traitement thermique du liquide et la mise en solution sur les caractéristiques des particules du silicium eutectique et les propriétés de traction de l'alliage A356 /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2005. http://theses.uqac.ca.

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39

Hwang, Junyeon Kaufman M. J. "Characterization and mechanical properties of nanoscale precipitates in modified Al-Si-Cu alloys using transmission electron microscopy and 3D atom probe tomography." [Denton, Tex.] : University of North Texas, 2007. http://digital.library.unt.edu/permalink/meta-dc-3661.

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40

Lee, Jonghee. "Fracture analysis of a propagating crack in a ductile material /." Thesis, Connect to this title online; UW restricted, 1996. http://hdl.handle.net/1773/7081.

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41

Zafari, Farzad. "Experimental and numberical study of elastic-plastic mixed-mode fracture /." Thesis, Connect to this title online; UW restricted, 1997. http://hdl.handle.net/1773/7034.

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42

Schaffer, Paul. "Grain refiner fade in aluminium alloys /." [St. Lucia, Qld.], 2004. http://www.library.uq.edu.au/pdfserve.php?image=thesisabs/absthe18566.pdf.

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43

Gammie, Shantel. "Process improvement to the anodize line through design of experiments /." Online version of thesis, 1996. http://hdl.handle.net/1850/11948.

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44

Pekgüleryüz, Mihriban Özden. "Strontium dissolution in liquid aluminum and A356 alloys." Thesis, McGill University, 1987. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=75438.

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The dissolution mechanism and kinetics of a number of strontium master alloys in liquid aluminum and A356 alloys have been investigated. The dissolution behaviour of the strontium alloys was found to show marked differences depending on strontium content. Dilute strontium alloys containing less than 63 weight percent Sr were observed to exhibit simple dissolution in both melts. The dissolution rate and the recoveries of these alloys were found to increase with increasing melt temperature. Over the temperature interval of 675-775$ sp circ$C dissolution was determined to be mass-transfer controlled with associated activation energies of 10-20 kcal/mole. Experimental rate constants for dissolution showed good agreement with a mass transfer correlation expressed as k = (0.67(Gr.Sc)$ sp{1/4}$ + 0.58(h/r)) (D/h). The dissolution of high strontium master alloys $(>$63 wt. pct. Sr), unlike the dilute alloys, was accompanied by the formation of various intermetallics. Additions at low melt temperatures yielded the exothermic formation of those intermetallics that have the lowest Sr content as seen in the relevant phase diagram, i.e., SrAl$ sb4$ in liquid Al and SrAl$ sb2$Si$ sb2$ in liquid A356. Due to low reaction rates at these low melt temperatures, these intermetallics formed as dispersed particles that could easily dissolve in the melt yielding high recoveries. At high melt temperatures, the associated chemical reactions yielded, as products, the higher Sr intermetallics which formed with little or no exothermicity. These intermetallics were observed to be scarcely soluble in the melt resulting in low strontium recoveries. The dissolution times of these alloys were found to show good agreement with calculated values based on a two-stage dissolution model comprising an initial exothermic reaction period and a subsequent free dissolution period. The strontium master alloys were classified in two groups; the high Sr alloys that are efficient at low temperatures of 675-7

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45

Lepage, Carl. "Effets des éléments alliés et des traitements thermiques sur la microstructure et les propriétés de traction des alliages aluminium-silicium 413.0 /." Thèse, Chicoutimi : Université du Québec à Chicoutimi, 2003. http://theses.uqac.ca.

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46

Vasudevan, Satish. "AN INVESTIGATION OF QUASI-STATIC BEHAVIOR, HIGH CYCLE FATIGUE AND FINAL FRACTURE BEHAVIOR OFALUMINUM ALLOY 2024 AND ALUMINUM ALLOY 2219." Akron, OH : University of Akron, 2007. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=akron1193668130.

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Thesis (M.S.)--University of Akron, Dept. of Mechanical Engineering, 2007.
"December, 2007." Title from electronic thesis title page (viewed 02/23/2008) Advisor, T. S. Srivatsan; Faculty readers, Craig Menzemer, Amit Prakash; Department Chair, Celal Batur; Dean of the College, George K. Haritos; Dean of the Graduate School, George R. Newkome. Includes bibliographical references.

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47

McMahon, Michael Edward. "Grain boundary development in superplastic aluminum alloys." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 1996. http://handle.dtic.mil/100.2/ADA325170.

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Dissertation (Ph.D. in Mechanical Engineering) Naval Postgraduate School, December 1996.
Dissertation supervisor(s): T.R. McNelley. "December 1996." Includes bibliographical references (p. 195-203). Also available online.

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48

Wilms, Ulrich H. "Shrinkage and microstructure in zinc-aluminum alloys." Thesis, Georgia Institute of Technology, 1986. http://hdl.handle.net/1853/17263.

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49

Ranganathan, Kannan. "Recrystallization resistance in aluminum alloys containing zirconium." Diss., Georgia Institute of Technology, 1991. http://hdl.handle.net/1853/19560.

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50

Jaansalu, Kevin Michael. "Composites by directed oxidation of aluminum alloys." Thesis, McGill University, 1991. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=60591.

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The manufacture of ceramic composites has traditionally been a complex and often expensive process. A new processing method, the DIMOX$ sp{ rm TM}$ process, takes advantage of the high temperature oxidation behaviour of aluminum alloys to produce a ceramic-metal composite. Although this process is fairly simple to implement, there has not been any attempt to link the starting materials and manufacturing conditions to the properties of the final composite. This work attempts to identify some critical parameters in the manufacturing process and how they affect the end product. The reaction temperature, alloy composition, and powder bed condition were optimized with respect to the growth process, final composition, and resulting microstructure. These characteristics were then related to the elasticity, strength, fracture toughness, and fracture mode of the final composite.
Aluminum-magnesium-silicon alloys were oxidized into an alumina bed of either Alcan C-70 UNG power or Struers' 400 grit. The process conditions were optimized in air at 1120$ sp circ$C with a 10% silicon, 2% magnesium alloy. The growth rate was dependent on the powder bed. The material was composed of alumina, silicon, aluminum, and trace amounts of magnesium aluminate spinel. The fracture mode was dependent on the composition of the material and the alumina bed.

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Dissertations / Theses on the topic 'Aluminum alloys'

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