Development of Ir based tool for friction stir welding of high temperature materials

A friction stir welding (FSW) tool with good properties at elevated temperature is needed to perform the friction stir welding of high temperature materials. One of the reasons for delaying the application of FSW to high temperature metals is the absence of such a tool. The purpose of this study was to develop a welding tool for the FSW of high temperature materials. As a result, it has been clarified that iridium (Ir) is almost unaffected by oxidation at elevated temperatures. The Ir alloy increases its recrystallization temperature, high-temperature strength and high-temperature hardness by the addition of rhenium (Re). Although SUS304 stainless steel was friction stir welded by an Ir-10at%Re welding tool, the tool was hardly deformed.