FRICTION STIR WELDING OF COPPER ALLOYS BY PTA HARDFACED TUNGSTEN CARBIDE TOOLS

摘要

In the present work an attempt was made to develop high temperature wear resistant hardfacing tools for friction stir welding (FSW) of commercial grade copper alloy. Hardfacing was applied on mild steel rod using Tungsten carbide forming powder by plasma transferred arc hardfacing (PTA) 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 joints. 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.