Development of high strength Ir based alloy tool for friction stir welding

The friction stir welding (FSW) tools for high temperature materials are required to have high performance at elevated temperatures. The purposes of this study are to strengthen iridium with an excellent oxidation resistance at elevated temperatures and to develop an FSW tool for high temperature materials. As a result, it was clarified that Ir based alloys are strengthened by the addition of elements with a larger atomic radius than that of Ir, and Zr was the most effective element in this study. Ir–10Re–1Zr has excellent mechanical properties and oxidation resistance at elevated temperatures. The FSW tool made from this alloy was hardly worn even if the SUS 304 stainless steel was friction stir welded.