Microstructural evolution and mechanical properties of friction stir welded ODS alloy MA754

Microstructural evolution and mechanical properties of MA754, an yttrium oxide dispersion-strengthened nickel-based superalloy, were investigated after friction stir welding (FSW). A tool rotation rate of 1000 revolution per minute and a traverse speed of 50.8 mm per minute were employed using a cermet (WC-Co) tool. After FSW, fine equiaxed grain structure with a high dislocation density and a random texture was achieved. Agglomeration of yttrium oxide dispersoids was observed in FSW MA754. Room-temperature tensile properties of FSW MA754 were compared to those of as-received MA754 alloy, and the results indicated that particle strengthening contribution decreased as a result of dispersoid agglomeration.