Al/Zn异种金属FSW对接接头组织及力学性能研究

Study on Microstructure and Mechanical Properties of Al/Zn Butt Welded Joints by Friction Stir Welding

为了获得在汽车工业中具有广泛应用前景的Al/Zn复合构件,采用搅拌摩擦焊的方法以3 mm厚2A14铝合金和加工态纯锌为试验材料,研究了其焊接接头的力学性能及微观组织结构。结果表明:当搅拌头旋转速度为500r/min、焊接速度为70 mm/min时,能获得焊缝成形良好、界面成"双钩状"的对接接头,此时接头抗拉强度达到最大值152.7 MPa,为母材锌的80.4%。钩状区铝合金和锌充分混合,出现局部洋葱环、冲击平原等形貌,且区域中形成了不同固溶体,固溶体类型从锌侧向铝侧由锌基固溶体向铝基固溶体转变。

In order to obtain Al/Zn composite component which has wide application prospects in the automotive industry, taking 2A14 aluminum alloy with 3 mm thickness and pure zinc of processing state as experimental materials, the mechanical properties and microstructure of the welded joint were studied through friction stir welding （FSW） method. The results indicate that the well-formed and ＂double-hook-like＂ butt joint can be fabricated by friction stir welding under the parameters that welding velocity is 70 mm/min, and rotation speed is 500 r/min, thus the tensile strength reaches to 152.7 MPa, which is nearly 80.4% of the zinc. Aluminum alloy and zinc mix sufficiently in hook-like region where local onion rings and alluvial plain morphologies appear, and different solid solution is generated in the region; those type changes from zinc-based to aluminum-based from zinc side to aluminum side.