Ultrasonic brazing of high fraction volume of SiC particulate reinforced aluminium matrix composites

Abstract

The ultrasonic brazing of 55 vol.-%SiC_p/A356 composites in air has been investigated. When the ultrasonic vibration is applied for 0·5 s, the oxide layer is still continuous at most places between the filler metal and the composites. As the ultrasonic action time increases, the oxide film sufficiently disappears in the bond region, resulting in the complete wetting of Zn–Al alloy with the composites and the significant mass transfer between the SiC/A356 and the Zn–Al alloy is observed. As the dissolving of the composites on the surface, the SiC particles in the base materials get into the bond metals in which reinforcements are distributed uniformly. The shear strength of bonds increases with the ultrasonic acting time.