Friction Stir Welding of Copper Alloys by PTA Hardfaced Chromium Carbide Tools

In the present work an attempt was made to develop high temperature wear resistant hardfaced tools for friction stir welding (FSW) of commercial grade copper alloys. Hardfacing was applied on mild steel rod using chromium carbide forming powder by plasma transferred arc (PTA) hardfacing process. Commercially available tool materials like high carbon steel (HCS), high speed steel (HSS) and super high speed steel (SHSS) were also used to friction stir weld copper alloy for comparison purpose. From this investigation, it is found that the PTA hardfaced tool yielded defect free joints without tool wear compared to other tools. The optimum level of heat generation, formation of finer grains and higher hardness of stir zone are main reasons for the superior tensile properties of the joints fabricated by PTA hardfaced tungsten carbide tools.