EUROPEAN CONGRESS AND EXHIBITION ON ADVANCED MATERIALS AND PROCESSES - EUROMAT 2021

In this study, interfacial morphology, microstructure and mechanical property of joints produced by explosive welding between Mg alloys AZ31, AZ61 and AZ80 and Al alloy A6N01 were investigated. In all joined plates, the bonding interface has a periodic wavy shape. In the Al matrix side, deformed grains were observed near the bonding interface, while recrystallized grains were observed in the Mg matrix side. Microstructure observation by TEM revealed that thin layer of intermetallic compound (IMC) was formed at the bonding interface in all joined plates and increasing the Mg composition in Mg alloy results in an increase of the thickness of IMC layer. In AZ80/A6N01 joined plate, IMC layer was formed uniformly at the bonding interface and the thickness of it was 1μm. The shear strength of AZ31/A6N01 and AZ61/A6N01 joined plates was about 148 MPa. For AZ80/A6N01 joined plate, shear strength reached up to 160 MPa. Therefore, explosive welding is effective to suppress the formation of IMC layer at the bonding interface during joining and maintain high shear strength of Mg alloy/Al alloy joined plates. The X-ray measurement Using synchrotron radiation　of stress on the bonding surface of joined plates revealed that compressive residual stress was generated in Mg alloy and tensile residual stress was generated in Al alloy. This difference is considered to be due to the difference between Mg alloy and Al alloy in thermal expansion coefficient.