Machining Mechanism and Residual Stress of AlCuCrFeNi Alloy

This investigation utilizes molecular dynamics simulations to explore the mechanical response of the AlCuCrFeNi high-entropy alloy to nano-scraping employing an abrasive tip traversing the workpiece surface. This study investigates the influence of various parameters, such as grain size, pressing depth, alloy composition, temperature, and sliding distance, on plastic deformation, frictional behavior, dislocation density, wear mechanisms, and von Mises stress. The results reveal that increasing grain size leads to augmented force and hardness, indicative of a reverse Hall-Petch relationship. Moreover, scraping and indentation forces escalate with decreasing aluminum concentration and temperature. The analysis underscores the pivotal role of grain boundaries in impeding stress and strain propagation. Stress and strain concentrations are particularly evident at the interface between the scraping tool and the substrate and near the grain boundaries. Grain boundary slipping, bending, and grain merging are pivotal mechanisms contributing to the distortion of polycrystalline materials, culminating in solid dislocations within grain boundaries. Furthermore, heightened compression depth and sliding distance exacerbate plastic deformation and subsurface damage. Notably, the presence of copper atoms enhances the HEA's resistance to deformation. This research enhances comprehension of the nano-scraping behavior and deformation mechanisms in AlCuCrFeNi HEA during ultra-precision processing.