Investigation on Multi-Pass Ultra-Precision Cutting of Sapphire Using Molecular Dynamic Simulations

Sapphire (α-Al₂O₃) is a material with numerous preferable mechanical properties such as high mechanical strength, high thermal and electrical resistivities, and light transmittance, thus having a wide range of applications. However, due to its inherent brittleness, its machinability has been proven to be a challenging roadblock in its versatility. To avoid fracture during the machining process, the ductile mode cutting mechanisms activated through ultra-precision cutting are investigated via the applications of molecular dynamic simulation. Specifically, this presentation discusses the effects of the number of passes on the cutting process and how the deformation mechanisms change when multi-pass cutting is applied to different crystallographic orientations of sapphire. The results suggest that the optimization of multi-pass cuts can significantly increase the critical depth of cut below which the crystal deforms in a ductile manner without significant fractures initiating.