Surface formation in laser-assisted grinding high-strength alloys

Laser-assisted machining is a promising method to achieve high efficiency and low damage when machining high-strength alloys. To explore the surface formation in laser-assisted grinding high-strength alloys, laser-assisted scratching was performed on a typical high-strength TC17 titanium alloy material using molecular dynamics simulations and experiments at different laser powers. The scratch force, material removal efficiency based on the scratched surface, and subsurface damage were analysed to determine the laser effects. A smaller scratch force can be achieved by laser assistance, and an appropriate laser power can enhance the material removal efficiency. The molecular dynamics simulation results were consistent with those of the experiments, and the subsurface formation process could be characterised by molecular dynamics simulations. In the laser-assisted scratched subsurface, three layers were found to differ from the matrix: amorphous, ultra-refined, and refined layers. The ultra-refined and refined layers were governed by continuous and discontinuous dynamic recrystallisation mechanisms, respectively, accompanied by different features through transmission electron microscopy analysis. These layers were shallower than those in the conventional scratched subsurface because of the annealing effect and smaller scratch force. In particular, annealing plays an important role in the amorphous layer of the machined surface. Laser-assisted belt grinding experiments were conducted for validation. This study provides significant insights into the low surface damage mechanism of high-strength alloys using laser-assisted machining.