Numerical Modeling and Experimental Study of Laser Assisted Machining of Fused Silica

Abstract

Fused silica is a kind of high-strength optical material, which is widely used in industry. It is slow and inefficient to process hard and brittle materials by conventional machining (CM) methods, while laser-assisted machining (LAM) technology can improve the plastic cutting ability of materials by local heating and softening, despite its application was not yet carried out in the case of fused silica. In this paper, the smoothed particle hydrodynamics (SPH) method is used to simulate the LAM process of fused silica. The result of LAM simulations show that the chips consist of continuous and discontinuous regions, which is significantly different from the CM in which the crack propagates and breaks in the initial deformation region. This indicates that the material removal mechanism takes place in a hybrid mode, which is a mixture of a brittle fracture and a plastic deformation. And the effect of process parameters on machining surface integrity, tool stress and tool wear were studied by numerical model. Both the simulations and the experimental results demonstrate that LAM significantly improves the machinability of fused silica by reducing the cutting force, improving the machining quality and decreasing the tool wear.