Interfacial Bonding and Mechanical Properties of Al/Mg Dissimilar Refill Friction Stir Spot Welds Using a Grooved Tool
Interfacial Bonding and Mechanical Properties of Al/Mg Dissimilar Refill Friction Stir Spot Welds Using a Grooved Tool
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DOI：
10.3390/cryst11040429
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发表时间：
2021-04
期刊：
影响因子：
2.7
通讯作者：
Z. Shen;Xinyu Liu;Dongxiao Li;Yuquan Ding;W. Hou;Hai-yan Chen;Wenya Li;A. Gerlich
中科院分区：
文献类型：
--
作者：
Z. Shen;Xinyu Liu;Dongxiao Li;Yuquan Ding;W. Hou;Hai-yan Chen;Wenya Li;A. Gerlich
使用沟槽套筒工具通过再填充搅拌摩擦点焊成功地制造了 Al/Mg 异种焊缝。从焊接参数优化、界面结合机制、硬度分布和焊接接头强度等方面系统评价了套筒熔深和转速对焊缝成型和力学性能的影响。结果表明，铝合金与镁合金的接合成功与否很大程度上取决于工具套筒的穿透深度。界面结合机制损害了冶金结合和机械互锁。 Al/Mg界面处形成Al3Mg2和Al12Mg17金属间化合物层。当转速从 1000 rpm 增加到 2000 rpm 时，焊接中心金属间化合物 (IMC) 层的厚度从 20–30 μm 增加到 40 μm。 Al 7075 的最小硬度为 80 HV，ZEK 100 的最小硬度为 52 HV；两者都是在热影响区测量的。随着转速的增加，焊接接头搭接剪切强度降低，散布量增大，当转速为1000 rpm时，散布量最大为3.6 kN。此外，失效机理由工具转速决定，发现转速为1000rpm时为界面失效，转速为2000rpm时为熔核拔出。
Al/Mg dissimilar welds were successfully fabricated by refill friction stir spot welding using a grooved sleeve tool. Influences of sleeve penetration depth and rotational speed on the weld formation and mechanical performance were systematically evaluated in terms of welding parameter optimization, interfacial bonding mechanism, hardness distribution and welded joint strength. The results indicated that the success of joining Al alloy to Mg alloy significantly depends on tool sleeve penetration depth. The interfacial bonding mechanism compromised both metallurgical bonding and mechanical inter-locking. Intermetallic compound layers of Al3Mg2 and Al12Mg17 were formed at the Al/Mg interface. The thickness of the intermetallic compound (IMC) layer at the weld center increased from 20–30 μm to 40 μm when the rotational speed increased from 1000 to 2000 rpm. The minimum hardness was 80 HV in Al 7075 and 52 HV in ZEK 100; both were measured in the heat affected zone. The welded joint lap shear strength decreased, and the scatter increased with the increasing of rotation speed, whose maximum was 3.6 kN when the rotational speed was 1000 rpm. In addition, the failure mechanism was determined by tool rotational speed, and found to be interfacial failure under a rotational speed of 1000 rpm and nugget pullout under a rotational speed of 2000 rpm.