Investigation on mechanism of ultrasonic welding AZ31B/5052 joint with laser texturing on mental surface

The ultrasonic welding was carried out to improve the quality of dissimilar Al/Mg alloy joint. The effects of laser texturing on the microstructure and mechanism of AZ31B/5052 joint connected by ultrasonic welding were also investigated. A series of laser texturing experiments on Al alloy (5052) and Mg alloy (AZ31B) were performed to determine the process parameters and their effect on ultrasonic weld quality, especially on weld strength. Little effect was attained by optimizing welding parameters in improving mechanical properties. Both welding parameters and different texture pattern were investigated to obtain good weld quality. The connection mechanisms of joints were discussed based on the analysis of weld interface morphology and microstructure evolution. Mechanical analysis of particle and movement of material atoms were analyzed in the study to explain the connect mechanism. The results show that the better lock-interface and lager lap shear strength were attained by laser texture addition and optimal welding parameters. Compared with the untextured joint, swirling bonding interface was obtained after the laser texture. The laser texture with grid pattern was found to raise the strength up to 26% higher maximum tensile-shear load than the joints obtained with the untextured surface.