Surface modification of brittle polycrystalline materials by laser-assisted rolling

This study proposes a novel surface modification method known as laser-assisted rolling, which aims to refine surface grains and enhance the machinability of brittle polycrystalline materials. This method establishes a foundation for achieving a crack-free and low-damage optical surface finish. Using binderless tungsten carbide as a case study, a systematic experimental investigation was carried out with a self-developed laser-assisted rolling system. The results show that the proposed method effectively refines surface grains by introducing dense defects. It also achieves a gradient grain size crystal structure and a residual compressive stress state without causing surface cracks. The formation and evolution mechanisms of the modified layer were comprehensively studied. Moreover, this novel method is expected to offer theoretical guidance for the surface modification of other brittle polycrystalline materials.