Surface Recrystallization in a Co-Based Superalloy During High Temperature Exposure

The effect of grinding on static recrystallization and oxidation of a novel Co-based superalloy has been studied. The evolution of surface recrystallization after heat treating at 850 °C in air was revealed by comparing ground specimens with electropolished ones. The loss of Al and Ti from the bulk material leads to the formation of a γ ′-free region and further promotes recrystallization at the surface.