Wear characteristics of a WC-Co tool in friction stir welding of AC4A+30Â vol%SiCp composite

Tool wear is a key issue for the friction stir welding (FSW) of aluminum matrix composites (AMCs), especially when the volume fraction of reinforcing particulates is relatively high. In this study, a threaded tool of WC-Co hard alloy is used to weld a cast AMC composed of Al-Si matrix and 30 vol%SiC particulates so as to examine the wear characteristics of the tool. Experimental results indicate that the tool wear is appreciable although the shoulder size and pin length are changed slightly. The radial wear of the pin is very different at different locations of the pin, and the maximum wear is finally produced at a location of about one-third pin length from the pin root. The welding speed has a decisive effect on radial wear rate of the pin, and the maximum wear rate is produced in the initial welding.