چکیده مقاله
In this study, thermo mechanical stability of two pass constrained groove pressing CGP AA1050 sheets towards friction stir welding FSW employing hybrid powder 50%vol micrometric graphite powder 50%vol α Al2O3 nanoparticles was investigated by examining its microstructural evolutions and mechanical properties FSW was carried out via different process variables in order to reach the highest ultimate mechanical properties of joints The welding variables employed in this study were single pass and multi pass FSW, and different rotation speed to traverse speed ratios ω/v were In order to appraise the powder effect on mechanical properties in the fabricated hybrid metal matrix composite HMMC , some CGPed sheets were also welded with no powder Besides optical microscopy and field emission scanning electron microscopy FESEM observations, Vickers microhardness and transverse tensile tests were conducted to examine mechanical properties of the weld zone It was revealed that the effect of graphite powder as a solid lubricant was substantially influenced by the welding variables More precisely, graphite powder contributed to the thermo mechanical stability of CGPed aluminum and thus, enhanced mechanical properties On the other hand, graphite powder can be responsible for mechanical properties drop due to deteriorating material flow In addition, different strengthening mechanisms, including grain boundary Zener pinning and particulate stimulated nucleation PSN mechanism, were provided and governed by both powders However, increasing the ω/v ratio was a practical approach to obtain uniform powder distribution, and consequently, to attainultimate mechanical properties Moreover, weld soundness was perceived to be achievable by increasing the number of FSW passes due to eliminating the cavities and improved material flow, reaching the optimum efficiency of ~ 80% in three pass FSW at ω/v=25
کلیدواژهها
نویسندگان
Seyyed Ezzatollah Moosavi
M Sc Student, Sharif University of Technology, Iran
مجتبی موحدی
Associate professor, Sharif University of Technology
Mohsen Kazeminezhad
Professor, Sharif University of Technology
شیوه ارجاع
Moosavi, Seyyed Ezzatollah and Movahedi, Mojtaba and Kazeminezhad, Mohsen,1400,Thermo-mechanical stability of severely plastic deformed aluminum joined by friction stir welding and graphite/Al2O3 hybrid powder: The effect of rotation speed to traverse speed ratio and number of welding passes,4th International Conference on Welding and Non Destructive Testing & 22nd National Conference on Welding & Inspection & 11th National Conference on NDT,Isfahan
ارائهشده در
مجموعه مقالات چهارمین کنفرانس بین المللی جوشکاری و آزمایش های غیرمخرب و بیست و دومین کنفرانس ملی جوش و بازرسی و یازدهمین کنفرانس ملی آزمایش های غیرمخرب18 اسفند 1400 · اصفهان