Experimental and theoretical investigation on the ductile removal mechanism in in-situ laser assisted diamond cutting of fused silica

Abstract

Laser assistance and the use of a diamond tool with a negative rake angle are promising methods for machining hard and brittle materials. In this paper, a cutting force model and a smoothed particle hydrodynamics (SPH) model were constructed to investigate the ductile removal mechanism of fused silica. Subsequently, in-situ laser assisted diamond cutting (LADC) experiments were performed to demonstrate the critical depth of cut (DOC), cutting force, and surface quality. As expected, the developed theoretical model demonstrated satisfactory accuracy in predicting the cutting force, with an error rate confined to 12%. Results indicated that the ductile machinability was enhanced with laser assistance due to a decrease in hardness, and the initiation of brittle fracture was reduced by high hydrostatic compressive stress when using a tool with a negative rake angle. A smooth and homogenous surface of fused silica with a surface roughness (Sa) of 13.8 nm was achieved for the application of a diamond tool with a rake angle of −65°.