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Vahid Fahimpour |
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Master Graduate of Materials Science and Engineering |
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Research Projects B.Sc. Thesis |
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Title: Investigation of Friction Stir Welding on Welded Regions Properties of Al6061 Alloys Supervisor: Associate Professor F. Karimzadeh Grade: 20/20 Abstract: Because of various applications of aluminum alloys in automobile and aerospace engineering, using a suitable welding process is very essential. In this research, friction stir welding as a solid state process and gas tungsten arc welding as a traditional melting process were used for square-butt welding of 13mm-thick metal sheets. Microstructures, mechanical properties and their corrosion resistance were studied. Results showed that FSW resulted in structures with grain sizes of about 1-2 micrometers in solidified weld metal. However, GTAW process formed a dendritic structure in this region. Evaluations show that although corrosion resistance is somewhat poorer in the welded regions compared to the base metal, FSW process has resulted in better corrosion behavior. The center-line dendrite emergence and micro-hardness reduction in the heat-affected zone (HAZ) were observed in the GTAW process. Although similar micro-hardness reduction with respect to the base metal was observed in the FSW samples, higher HVs were however obtained for the FSW than the GTAW process at almost all heat affected locations. Ultimate tensile strengths of the FSW and the GTAW welds in transverse direction were ~0.57 and ~0.35 of the base-metal, respectively. Post-weld aging recovered the strength but reduced the ductility of the welding. Also T6 heat treatment of the alloy improved its corrosion behavior and corrosion potential was higher compared to the base metal. Keywords: Frictions stir welding; Gas tungsten arc welding; Al6061 alloy; Microstructure; Mechanical properties; Corrosion resistance; Heat treatment. Publications: 2. V. Fahimpour, S.K. Sadrnezhaad and F. Karimzadeh, Microstructure and mechanical property change during FSW and GTAW welding of Al6061 alloy, Metallurgical and Materials Transactions A. |
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B.Sc. Thesis |
contact:Vahid.fahimpour@gmail.com |
