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- Type of Document: M.Sc. Thesis
- Language: Farsi
- Document No: 40147 (07)
- University: Sharif University of Technology
- Department: Materials Science and Engineering
- Advisor(s): Ashuri, Hossein
- Abstract:
- Semisolid joining is a relatively new method that is started since 2002. So far, Aluminum alloys semisolid joining is not studied in details. In this research, by obtaining local semisolid region in the vicinity of the joining seam, two A356 Aluminum part were welded. Hot Nitrogen gas was used to prepare local semisolid region. Since the hot gas was not capable to produce the region by itself, samples were preheated. In experimental procedure, preheating plane type, hot gas temperature, gas flow, sample dimensions, and welding speed were investigated. Effects of each parameter were determined by microstructure studies and measuring the mechanical properties of welding seam. Results showed that the most appropriate preheating plane type is local radiation plane. Also, high speed joining results in non-steady state in the final part. Higher gas flow reduced essential gas temperature and could also reduce heat affected zone. Increase in temperature promoted final welding properties. Investigating the joining zone temperatures showed that at liquid fractions less than 20 % joining were not fully practical. At 20-35 % the WM region and at 35-60 % the welding sides had the poorest properties. At 60-70 % the whole welding zone and the substrate metal properties would be closely similar
- Keywords:
- Local Semisolid Regian ; Aluminum Alloy A356 ; Shear Punch Test ; Localized Stirring ; Liquid Fraction
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