Friction stir welding of oxide dispersion strengthened platinum alloy

The FSW of an oxide dispersion strengthened platinum alloy using an Ir-based alloy tool was performed. When the welding temperature during FSW was lower than the annealing temperature, abnormal grain growth was seen in the joint after annealing. On the other hand, the microstructure of the joint after annealing maintained finer grains when the welding temperature was higher than the annealing temperature. When the finer grain was maintained, the hardness of the joint after annealing was the same as before annealing and the tensile specimens fractured at the base metal part at room temperature. However, the tensile specimens fractured at stir zone with a large deformation during the high temperature tensile test at 1500°C.