Study on microstructure evolution and recrystallization behavior of nickel-based superalloy robot abrasive belt grinding surface under high-temperature exposure

Abstract

The interference between grits and workpiece material during the nickel-based superalloy robot abrasive belt grinding process can cause plastic deformation on the grinding surface, and the evolution of surface deformation microstructure under high-temperature conditions can affect the surface properties of superalloys. Therefore, a high-temperature exposure experiment is devised in this paper, and electron backscatter diffraction (EBSD) and scanning electron microscopy (SEM) are used as characterization methods to study the microstructure evolution characteristics and recrystallization behavior of nickel-based superalloy robot abrasive belt grinding surface under high-temperature exposure. In addition, the effects of grinding factors (abrasive belt grit size and normal contact force) on high-temperature exposure recrystallization of grinding surface are explored. The research results indicate that under high-temperature exposure, the surface deformation microstructure consumes dislocations and releases stored energy, evolving into fine equiaxed recrystallized grains within the original grains through subgrain growth nucleation and grain boundary migration. Meanwhile, the recrystallization process is accompanied by twin formation. The recrystallization process is affected by the exposure temperature and time, and exposure temperature has a decisive influence on recrystallization. Furthermore, both the abrasive belt grit size and normal contact force have a profound influence on the recrystallized grain size and the recrystallization area depth.