Towards understanding the deformation mechanism of high-entropy alloy after in-situ laser-assisted diamond cutting : from macro material removal features to micro atomic arrangement patterns

Abstract

In-situ laser-assisted diamond cutting (LADC) technology demonstrates significant advantages over conventional diamond cutting (DC) for machining advanced high-performance materials. However, most current research focuses on the improvement of the surface integrity achieved by in-situ LADC, while the understanding of deformation mechanisms remains insufficient and incomplete, especially for novel multi-principal element high-entropy alloy (HEA) materials. To address this research gap, the HEA workpieces subjected to in-situ LADC machining are thoroughly investigated to explore the material transformations under the synergistic effects of the laser energy field and mechanical shearing. Advanced characterization techniques are utilized to systematically analyze the constitutive behavior of HEA materials during in-situ LADC machining, spanning macroscale micrometer-level material removal features to microscale nanometer-level atomic arrangement patterns. The results indicate that, at the macroscopic level, the thermal softening effect of in-situ LADC technology not only enhances the surface quality of processed workpieces due to the improved machinability of HEA materials, but also prevents significant material buildup on the cutting edge of diamond tools. On a microscopic level, compared to the traditional DC processing where the multi-principal element and low stacking fault energy characteristics of HEA materials result in numerous stacking fault defects within the nanocrystalline grains of the near-surface recrystallization layer, the coupled thermal effect of laser-friction in in-situ LADC technology significantly improves the orderliness of atomic arrangements within the nanocrystalline grains. This study advances the fundamental understanding of in-situ LADC-induced material deformation mechanisms in HEA, providing critical insights to accelerate the application of laser-assisted technologies in multi-domain high-performance material processing.