LAUSR

Abstract This paper studied the effect and optimization of ultrasonically assisted single-sided lapping for monocrystalline SiC wafer using grey relational analysis method. 27 experiments based on the Taguchi method of orthogonal arrays were performed to determine the best factor level condition. Besides, the comparative experiments using three lapping plates (cast iron, copper, and aluminum) were also performed under ultrasonic lapping and non-ultrasonic lapping, respectively. Material removal rate (MRR) and surface roughness (Ra, Rmax) were selected as the output indexes. The degree of influence that the controllable process factors exert on the indexes was studied by investigating the correlation between them. By analyzing the signal-to-noise ratio and grey relational grade, the most influential process factor is the interaction item of normal pressure and rotating speed. Ultrasonically assisted vibration has a positive correlation with the MRR, while simultaneously increases the surface roughness, but the higher ultrasonic power is beneficial to inhibit the increase of surface roughness. The lower hardness of lapping plate can obtain the better surface at the cost of decreasing MRR, but much too low hardness may destroy the machined surface.