Liquid-solid composite bonding of femtosecond laser surface modified SiC ceramics and 7A52 aluminum alloy

This article proposes a method for achieving the connection of SiC and 7A52 aluminum alloy using femtosecond laser surface modification of SiC ceramics. The influence of laser power on the morphology, chemical composition, and wettability of the SiC ceramic surface and the liquid-solid composite bonding mechanism of SiC and 7A52 after femtosecond laser modification was investigated. After femtosecond laser modification, the ceramic structure was constructed with a periodic groove structure of appropriate size, which increased the bonding area between the solder and the ceramic surface. Additionally, thermal decomposition occurred on the SiC surface, resulting in a recasting layer, which improved the wetting effect of the solder on the ceramic surface and enhanced the diffusion of Al and Mg elements to the joint interface. The existence of periodic groove structures changes the fracture path of the joint and improves the strength of the liquid-solid composite joint, which is approximately 45.9 % higher than the original joint strength.