A laser assisted hybrid process chain for high removal rate machining of sintered silicon nitride

This paper presents a hybrid process chain for efficiently machining hard silicon nitride. The process includes a laser treatment phase to weaken the material, followed by diamond grinding. Optimized laser parameters have been identified to control the generation of a network of cracks that weakens the volume of material to be ground. Comparison of data between traditional and hybrid process chain shows a reduction in grinding force of about thirty per cent in the latter case. A finite element model has been developed for the analysis of thermal stresses generated by laser exposure and the prediction of crack formation.