Weld Nugget Zone Nanocomposite Formation of Al ۷۰۷۵-T۶/Al۲O۳ over Friction Stir Spot Welding Process and its Influence on Fatigue Response

This study intends to evaluate the impact of Al۲O۳ nanoparticles added into the stirred zone of Al ۷۰۷۵-T۶ joints on the mechanical behavior and fatigue life through Friction Stir Spot Welding (FSSW) process. Nanoparticles with different amounts of ۰.۰۲, and ۰.۰۵ grams were dispensed into the pre-existed small hole on the top of the lower plates, then the upper plates were placed on the lower plates following the welding operation to form localized composite FSSW joints. Tensile and fatigue strength of localized FSSW composite joints were then compared with those of as-welded samples. Stirred zone of joints holding ۰.۰۲ grams of Al۲O۳ nanoparticles slightly improved tensile strength while fatigue lives of nanocomposite joints were enhanced as high as ۲.۵ times as compared to as-welded joints. Inclusion of ۰.۰۵ grams Al۲O۳ nanoparticles in the nugget joint however resulted in no improvements in tensile and fatigue strengths.

کلیدواژه ها:

Friction stir spot welding ، Nanoparticles ، Weld nugget nanocomposite ، Fatigue strength