Study of Wear Rate and Micro-structure of Friction Stir Welded Joint

The effect of Friction stir welding on micro-structure, hardness and wear rate of Al-Cu alloy was measured in this study. Wear tests for cast aluminium alloy joint were conducted on a pin disc machine for different loads of 2-4 kg at constant sliding velocity. The pins were prepared from cast aluminium billets worn on En31 steel as counter body. Wear behavior and hardness for welded and unwelded portion were determined for the joint. The highest hardness value occurs in the center of the welded zone followed by a gradual decrease across the TMAZ and HAZ until reaching the hardness value of the base material. Hardness of each sample was co-related with the friction and wear behavior of cast aluminium alloy of FSW. Micro-structure of FSW was also obtained for weld zone (fusion zone)boundary (between weld zone & HAZ), heat affected zone and base metal region.