Microscopic grinding mechanism of γ/γ’ single crystals

Abstract

High-precision Ni-based alloy components are widely used in aerospace and other advanced applications. However, when machining accuracy reaches the micrometer scale or higher, the microstructure of the material must be considered. To uncover its microscopic grinding mechanisms, we employed molecular dynamics to study the grinding behavior of the alloy and its constituent phases. The results indicate that, compared to the γ single crystal (SC), the γ’ single crystal (SC) exhibits enhanced interatomic bonding due to the incorporation of Al atoms. Consequently, it experiences the highest subsurface residual stress and grinding temperature, leading to poorer grinding performance. Furthermore, under external forces, its activated slip surfaces are fewer, and the motion of dislocations is more restricted. In contrast, the two-phase γ/γ’ Ni-based SC combines the properties of both phases, demonstrating superior grinding performance. The presence of grain boundaries further impedes dislocation motion and leads to properties distinct from those of its constituent SCs.