Performance of Tungsten-Based Alloy Tool Developed for Friction Stir Welding of Austenitic Stainless Steel

摘要

As the cost-effective tool material, W-based alloys containing hard particles, exhibiting high strength, ductility, and thermal conductivity at high temperatures, were newly developed for FSW of austenitic stainless steel in this study. The W-based alloy tools containing various hard-particles were employed in FSW of type 304 austenitic stainless steel, and the wear behavior was examined. The W-based alloy tools coated by a ceramic exhibited the good performance during FSW, but the tool wear could not be completely prevented. Degree of the tool wear depended on the high-temperature strength, i.e., it decreased with increasing high-temperature strength. The tool wear was significantly suppressed in the W-based alloy with the higher high-temperature strength, and the tool shape was hardly changed even after the 20 m travel on the tool with 1.7 mm long probe.