Interface characteristics, microstructure, and mechanical properties of friction stir lap welded dissimilar Al/Mg alloy joints: effect of pin-tip profile

作者：Yang, Ping; Mao, Yuqing^*; Xu, Yang; Li, Ning; Ke, Liming; Chen, Yu

来源：INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY, 2022, 119(7-8): 5251-5260.

DOI：10.1007/s00170-021-08611-0

• Dissimilar Al
• Mg alloys
• Friction stir lap welding
• Pin-tip profile
• Interfacial microstructure
• Mechanical properties

Three pin-tip profiles of cylinder (C-tool), square (S-tool), and triangular (T-tool) were innovatively designed, and the effect of pin-tip profile on interfacial microstructure and mechanical properties of friction stir lap welded (FSLW) joints was investigated. The results show that the interface characteristics of FSLW joints fabricated by various pin-tip profiles are notably different. The upward migration of Mg alloy at the interface of S-tool and T-tool joints significantly reduces. Moreover, two intermetallic compound (IMC) layers (Al3Mg2 and Al12Mg17) with about 4.6-mu m thickness are formed on the interface bottom by C-tool. However, only one continuous IMC layer of and eutectic structure (Mg+Al12Mg17) on the Al side are generated at the interface by S-tool, and the interface by T-tool is composed of a discontinuous IMC layer and eutectic structure. The maximum tensile-shearing load of the joints welded by S-tool is obtained, which reaches 5.95 KN. The fractured location occurs along the eutectic structure layer on the Al side.

• 单位
  南昌航空大学