30mm厚7A52铝合金搅拌摩擦焊接组织与性能研究

针对30 mm厚的7A52铝合金,采用搅拌摩擦焊接技术进行单道焊接试验,利用光学显微镜等工具对焊接接头组织及力学特性进行研究。结果表明:沿焊缝区横截面的硬度分布呈现W形,TMAZ/HAZ过渡区为接头软化区,硬度最低值在前进侧的TMAZ/HAZ过渡区;焊接接头强度达到母材强度的85.8%,断裂于TMAZ/HAZ过渡区,为韧窝断口形貌。

Microstructure and properties of welding joints of 30 mm thickness 7A52 aluminium alloy plate by friction stir welding

The 7A52 aluminum alloy of 30 mm thickness was welded by friction stir welding. The microstructure and mechanical property of welded joint were studied by optical microscope and SEM,etc. The results show that the hardness distribution along cross section in welded zone is in the shape of W,ɑnd the TMAZ/HAZ transition zone of welded joint is the softening zone. The minimum of micro-hardness occurs on the TMAZ/HAZ transition zone of the advancing side. The tensile strength of weld reaches85.8% of base mental,fracture occurs in the TMAZ/HAZ transition zone,and the fracture morphology is dimple.