Vibration assisted brazing of SiC p /A356 composites: Microstructure and mechanical behaviour

Abstract

Vibration assisted brazing of SiCp/A356 composites in air was investigated. A vibration was applied on one of the samples to be bonded at 375°C during brazing. The filler metal was extruded reciprocally and impacted intensively and reciprocally on the two surfaces of the base materials during vibrating. It can be found that most of the oxide film on the surface of the composites was disrupted and removed through the observation by SEM. The metallurgical bonds formed between the filler metal and the base materials. However, a lot of porosities were entrapped in the bond metal. A vibration was once more applied after the samples were continuously heated up to 520°C, and any porosity could not be found. The bonds mainly composed of a new alloy, which have a higher content of aluminium and free of porosities, show a higher shear strength of 178 MPa comparing to that of the base materials.