Experimental Study of Machining Characteristics in Laser Induced Wet Grinding Silicon Nitride

Silicon nitride ceramics are extremely difficult and time-consuming to machine with conventional methods, such as turning and grinding. Laser-assisted machining has been a field of extensive research during the past decade, as it is a promising solution to enhance the machinability of many difficult-to-cut materials, including silicon nitride ceramics. To enhance the processing precision of silicon nitride ceramic grinding, this paper presents an experimental investigation of a two-stage laser-induced wet grinding (LIWG) process, including laser-induced thermal cracking and wet grinding. Specifically, the differences in the grinding force, grinding force ratio and surface roughness obtained for LIWG and conventional grinding (CG) conditions are compared and discussed. The normal and tangential grinding forces for LIWG condition were lower than for the CG condition with a maximum reduction of 70.4% (83.3%) for the maximum average normal (tangential) grinding forces. The values of the force ratio for the CG condition and LIWG condition were in the range of 3.7-5.5 and 6.5-11.5. Little improvement was achieved, and the surface roughness values are considerable for both conditions.