TY - JOUR N2 - Refill friction stir spot welding (RFSSW) was used to weld the 2060 aluminum alloy with 2 mm thickness. Joint formation, defect characteristics and mechanical properties were investigated. Results show that stir zone (SZ) is clarified into dynamic recrystallization zone (DRZ) and heat extruded zone (HEZ) due to different microstructural features. The size of void near the hook tip decreases with the increase of the plunge depth. Different hook morphologies are obtained under different plunge depths. The tensile-shear load of joint with the void defect initially decreases and then increases with increasing plunge depth. The mean loads of joints under different plunge depths are in the range of 5.1-5.8 kN. The void separates the hook from lap interface, so the cracks initiating from the hook propagate along the sleeve retreating path. The hook has a larger influence on the tensile-shear load of joint than void. All the tensile specimens present a shear-plug fracture mode. L1 - http://journals.pan.pl/Content/117800/PDF/AMM-2021-1-20-Shude%20Ji.pdf L2 - http://journals.pan.pl/Content/117800 PY - 2021 IS - No 1 EP - 161 DO - 10.24425/amm.2021.134771 KW - Refill friction stir spot welding KW - 2060 aluminum alloys KW - plunge depth KW - defect characteristics KW - mechanical properties A1 - Shang, Zhen A1 - Zuo, Yingying A1 - Ji, Shude A1 - Wang, Yue A1 - Chai, Peng PB - Institute of Metallurgy and Materials Science of Polish Academy of Sciences PB - Committee of Materials Engineering and Metallurgy of Polish Academy of Sciences VL - vol. 66 DA - 2020.12.22 T1 - Joint Formation and Mechanical Properties of 2060 Aluminum Alloy Refill Friction Stir Spot Welding Joint SP - 153 UR - http://journals.pan.pl/dlibra/publication/edition/117800 T2 - Archives of Metallurgy and Materials ER -