Interfacial Microstructure Evaluation of Precisely Controlled Friction Stir Welding Joints of Al/Mg Dissimilar Alloys with Zn Interlayer

作者：Wang, Gang; Xie, Jilin; Yin, Limeng; Chen, Yuhua^*

来源：Coatings, 2023, 13(7): 1149.

DOI：10.3390/coatings13071149

• Al
• Mg dissimilar metals
• friction stir welding
• Zn interlayer
• interfacial microstructure

In this study, a penetration-controlled friction stir welding (FSW) technique was employed to lap weld dissimilar Al/Mg alloys, incorporating a Zn interlayer. The joint's microstructure, interfacial reaction, and phase composition were analyzed through optical microscopy, scanning electron microscopy, and X-ray diffraction. The findings demonstrate the formation of a hybrid joint comprising a FSWed region and a diffusion bonding region achieved by introducing a pure Zn interlayer at the Al/Mg interface. Within the FSWed region, the zinc was fully extruded, leading to favorable interface bonding. In contrast, the diffusion bonding region exhibited an aluminum-zinc diffusion reaction layer, an incompletely reacted zinc layer, and a zinc-magnesium diffusion reaction layer. Notably, no Al-Mg intermetallic compounds (IMCs) were observed in either the FSWed or diffusion bonding regions of the hybrid joint. This study further explored the underlying mechanism behind the joint's formation.

• 单位
  南昌航空大学