【摘要】 对不同转速下含Zr中间层6061铝合金/AZ31镁合金搅拌摩擦焊搭接接头组织结构、力学性能、腐蚀行为的变化进行了研究。结果表明，Zr中间层抑制了接头表面飞边和内部隧道等缺陷，焊材通过搅拌区的机械互锁结构与搭接界面反应生成的金属间化合物实现了机械与冶金结合。随转速的提高，接头搅拌区内焊材的热塑性流动强度和机械互锁程度逐渐加强，其中的Zr碎片和条带组织尺寸有所变小；接头的热力影响区/搅拌区界面宽度及搭接界面宽度均趋于增大。接头横截面沿前进侧和后退侧的硬度分布不对称，在焊接中心线附近具有较高硬度；接头的拉伸剪切载荷随转速的提高先增加后减小，剪切断裂位置发生在接头热力影响区/搅拌区界面处。接头在3.5%NaCl溶液中具有差异化的腐蚀行为，铝合金以均匀腐蚀为主，镁合金以局部点蚀为主，Zr中间层未发生明显腐蚀，提高转速在一定程度上降低了接头的腐蚀性能。更多还原

【Abstract】 The microstructure, mechanical property and corrosion behavior of 6061 Al/AZ31 Mg friction stir welding lap joints with Zr interlayer at different rotation rates were investigated. The results show that the Zr interlayer suppresses the defects of flashes and tunnels. The welding materials are joined via the mechanical interlocking in the stir zone(SZ) and the intermetallic compounds are formed at the overlapping interface. The degree of thermoplastic flow and mechanical interlocking in the SZ increase with increasing rotation rate, which form smaller Zr fragments and thinner strips. The transitional widths of the thermal-mechanical affected zone(TMAZ)/SZ interface as well as the overlapping interface tend to increase as the rotation rate increases. The hardness distribution on the cross-sections of joints along advancing side and retreating side are asymmetric, which has higher hardness near the welding centerline. The tensile shear load of Al/Zr/Mg joints firstly increases and then decreases with increasing rotation rate and the fracture position is located at the TMAZ/SZ interface. The joints exhibit a differential corrosion behavior in the 3.5% NaCl solution. The Al alloy is uniformly corroded, the Mg alloy is locally pitting corroded and the Zr interlayer is not corroded. The corrosion resistance of joints is deteriorated in some degree with increasing rotation rate.更多还原