Evaluation of the stress ralaxation technique for measuring softening kinetics in aluminium alloys

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dc.contributor.advisorKnutsen, Robert Den_ZA
dc.contributor.authorGeorge, Sarahen_ZA
dc.date.accessioned2014-12-30T06:32:44Z
dc.date.available2014-12-30T06:32:44Z
dc.date.issued2006en_ZA
dc.descriptionIncludes bibliographical references.en_ZA
dc.description.abstractThe development of the microstructure during thennomechanical processing (TMP) is critical in determining the final properties and quality of metal strip. In the particular case where aluminium sheet is used for lithographic applications, the surface appearance after electro-etching should be devoid of any streaking or inhomogeneous discolouration. The cause of possible streaking effects can be related to poor microstructure development during TMP and often arises as a result of inadequate recrystallisation. To avoid the deleterious effects, it is important to implement the appropriate rolling conditions in order to control the processes of recovery and recrystallisation. The means by which the correct rolling conditions can be established is usually by extensive laboratory simulations and concomitant microstructural analysis. In view of the fact that this approach is often tedious, the present study has investigated the use of the stress relaxation technique to provide rapid data on the recovery and recrystallisation kinetics for commercial purity aluminium under defonnation conditions that closely simulate hot rolling operations. Stress relaxation (SR) curves have been generated for AA1200 aluminium, as well as for two magnesium containing alloys, namely AA5182 (5wt% Mg) and an experimental alloy (Al-l %Mg). Fully recrystallised microstructures were subjected to uniaxial compression in the temperature range of 300-400?C. Strains and strain rates were up to 0.7 and ls respectively. Stress relaxation was measured for intervals up to 15 minutes and the evolved microstructures were examined after fixed intervals using polarised light microscopy and electron backscatter diffraction.en_ZA
dc.identifier.apacitationGeorge, S. (2006). <i>Evaluation of the stress ralaxation technique for measuring softening kinetics in aluminium alloys</i>. (Thesis). University of Cape Town ,Faculty of Engineering & the Built Environment ,Centre for Materials Engineering. Retrieved from http://hdl.handle.net/11427/10498en_ZA
dc.identifier.chicagocitationGeorge, Sarah. <i>"Evaluation of the stress ralaxation technique for measuring softening kinetics in aluminium alloys."</i> Thesis., University of Cape Town ,Faculty of Engineering & the Built Environment ,Centre for Materials Engineering, 2006. http://hdl.handle.net/11427/10498en_ZA
dc.identifier.citationGeorge, S. 2006. Evaluation of the stress ralaxation technique for measuring softening kinetics in aluminium alloys. University of Cape Town.en_ZA
dc.identifier.ris TY - Thesis / Dissertation AU - George, Sarah AB - The development of the microstructure during thennomechanical processing (TMP) is critical in determining the final properties and quality of metal strip. In the particular case where aluminium sheet is used for lithographic applications, the surface appearance after electro-etching should be devoid of any streaking or inhomogeneous discolouration. The cause of possible streaking effects can be related to poor microstructure development during TMP and often arises as a result of inadequate recrystallisation. To avoid the deleterious effects, it is important to implement the appropriate rolling conditions in order to control the processes of recovery and recrystallisation. The means by which the correct rolling conditions can be established is usually by extensive laboratory simulations and concomitant microstructural analysis. In view of the fact that this approach is often tedious, the present study has investigated the use of the stress relaxation technique to provide rapid data on the recovery and recrystallisation kinetics for commercial purity aluminium under defonnation conditions that closely simulate hot rolling operations. Stress relaxation (SR) curves have been generated for AA1200 aluminium, as well as for two magnesium containing alloys, namely AA5182 (5wt% Mg) and an experimental alloy (Al-l %Mg). Fully recrystallised microstructures were subjected to uniaxial compression in the temperature range of 300-400?C. Strains and strain rates were up to 0.7 and ls respectively. Stress relaxation was measured for intervals up to 15 minutes and the evolved microstructures were examined after fixed intervals using polarised light microscopy and electron backscatter diffraction. DA - 2006 DB - OpenUCT DP - University of Cape Town LK - https://open.uct.ac.za PB - University of Cape Town PY - 2006 T1 - Evaluation of the stress ralaxation technique for measuring softening kinetics in aluminium alloys TI - Evaluation of the stress ralaxation technique for measuring softening kinetics in aluminium alloys UR - http://hdl.handle.net/11427/10498 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/10498
dc.identifier.vancouvercitationGeorge S. Evaluation of the stress ralaxation technique for measuring softening kinetics in aluminium alloys. [Thesis]. University of Cape Town ,Faculty of Engineering & the Built Environment ,Centre for Materials Engineering, 2006 [cited yyyy month dd]. Available from: http://hdl.handle.net/11427/10498en_ZA
dc.language.isoengen_ZA
dc.publisher.departmentCentre for Materials Engineeringen_ZA
dc.publisher.facultyFaculty of Engineering and the Built Environment
dc.publisher.institutionUniversity of Cape Town
dc.subject.otherEngineeringen_ZA
dc.titleEvaluation of the stress ralaxation technique for measuring softening kinetics in aluminium alloysen_ZA
dc.typeMaster Thesis
dc.type.qualificationlevelMasters
dc.type.qualificationnameMScen_ZA
uct.type.filetypeText
uct.type.filetypeImage
uct.type.publicationResearchen_ZA
uct.type.resourceThesisen_ZA
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