AN INVESTIGATION OF MECHANICAL PROPERTIES OF SHIELDED METAL ARC WELDING AND FRICTION STIR WELDING IN 7020-T6 AL ALLOY

摘要

Two different types of welds, shielded metal arc (SMA)welding and friction stir welding (FSW) have been used toweld Aluminum alloy 7020-T6.Investigation has been carried out on mechanical propertiessuch as (yield and tensile strength, impact, harnesses,ductility ,and microstructure) . The result shows that bothmethod could be used to weld such alloy although FSWweld show higher mechanical properties comparison toSMA with joint efficiency equal to 97% compared to 58%in SMA .The extension of the heat affected zone is higher in SMAmethod in comparison to the FSW and localized grain sizefor FSW in the stirred zone was 15-18 micron and it was 37-39 micron for SMA, while it was 32-35 micron for the basemetal.In general decay of mechanical properties of SMA joints,was due to high temperature experienced by the material,but in FSW joint lower temperature are involved in theprocess due to sever plastic deformation induced by the toolmotion.7020 Al alloy, FSW, SMA, mechanical properties.