(1. 天津大學 材料科學與工程學院，天津 300072；
2. 天津大學 天津市現(xiàn)代連接技術重點實驗室，天津 300072)
摘 要: 分別采用攪拌摩擦焊(FSW)單道焊和雙道焊工藝方法制備鋁合金T型接頭，對比分析單道、雙道FSW-T型接頭的缺陷、顯微組織、硬度及拉伸性能。結果表明：相對單道焊接頭，雙道焊工藝可有效降低FSW-T型接頭缺陷尺寸及改善缺陷分布狀態(tài)，隧道缺陷消失或面積降低，吻接缺陷長度降低；雙道焊接頭在前進側和后退側的組織和性能不均勻性明顯降低，軟化區(qū)范圍和差異減小；雙道焊接頭拉伸性能明顯提高，在筋板和壁板方向其拉伸性能普遍為母材的80%以上，明顯高于單道焊接頭的拉伸性能。
關鍵字: 6061-T4鋁合金；攪拌摩擦焊；T型接頭；雙道焊；力學性能
（1. College of Materials Science and Engineering, Tianjin University, Tianjin 300072, China;
2. Tianjin Key Laboratory of Advanced Joining Technology, Tianjin University, Tianjin 300072, China）
Abstract:6061-T4 aluminum alloy T-joints were jointed by friction stir welding under single pass and double passes. The welding defects, microstructure, hardness profiles and tensile strength under different welding passes were observed and discussed. The results show that, compared with the single pass welding joints, double passes welding joints have such advantages as follows, the size and distribution of defects are modified, the area of tunnel defects decreases or disappears and the kiss bonding decreases; the inhomogeneity of microstructure and property at advancing side and retreating side decreases greatly; besides, the area and difference of softened zone reduce; the tensile property improves evidently to 80% of that of the base metal, which is better than that of the single pass welding joints.
Key words: 6061-T4 aluminum alloy; friction stir welding; T-joint; double passes welding; mechanical property
