Abstract:Microstructure and mechanical properties of SiC_p/AA5083 composite fabricated by friction stir welding (FSW) were investigated. The influence of the number of FSW passes on the distribution of SiC particles and mechanical properties in the joint was studied. After one pass, the SiC particles were entangled in the upper side of the stir zone (SZ). However, the particle distribution became more uniform after two passes due to the repeated stirring of the joint. As the SiC particles facilitate the grain refinement in the SZ by the pinning effect, the particle including region has much smaller grain size than the SZ without SiC particles. The SiC_p/AA5083 composite region exhibits a Vickers hardness of HV90, which is much higher than the value of HV80 in the SZ produced by FSW without SiC particles.

Key words: metal matrix composite; SiC particle; friction stir welding; mechanical property