Plastic deformation mechanism of grinding subsurface of nickel-based single-crystal superalloy

Single-crystal materials have emerged as a new class of materials widely utilized in the aerospace field. This paper aims to study nickel-based single crystal superalloy DD5, a notoriously challenging material to process. Among the various machining techniques, grinding can achieve superior surface quality with minimal size errors, making it an ideal choice for this experiment. Consequently, this research utilizes the grinding method to investigate the subsurface deformation mechanism of nickel-based single crystal superalloy. To investigate the subsurface plastic damage layer in nickel-based single crystal superalloy, the Hollomon relationship is employed to elaborate on the subsurface plastic deformation mechanism. Furthermore, an effective removal thickness model of a single abrasive grain was established in this study to examine the impact of grinding on the subsurface of nickel-based single crystal superalloy DD5. The model analyzes the influencing factors of subsurface plastic deformation in the grinding process, evaluates the different grinding parameters' effects on the maximum plastic deformation of subsurface and plastic deformation thickness, and compares the simulation with experimental results. The findings indicate that the subsurface damage of the workpiece is primarily affected by the maximum plastic deformation rate, and the plastic deformation in the workpiece is typically influenced by material properties. Within the experimental parameters, the plastic deformation of nickel-based single crystal superalloy reduces with an increase in wheel speed while subsurface plastic deformation increases with a rise in feed rate and grinding depth. Among other processing parameters, the wheel speed has the most significant effect on subsurface plastic deformation during the grinding process.