Evaluation of grinding characteristics for sapphire ultra-precision grinding using small grit sizes wheels based on AE signals

This paper focused on the grinding characteristics for sapphire ultra-precision grinding with small grit size grinding wheels and acoustic emission signal monitoring of material removal mechanism under the action of multiple abrasive grain. The results show that the use of small grit size grinding wheels allowed for effective removal of sapphire and they facilitated the production of ductile surfaces at the correct parameters. The grinding depth was the most significant effect on the grinding characteristics, the grinding force and subsurface damage scale increased with the grinding depth, and the grinding surface morphology developed from ductile surface to low damage ductile surface and brittle fracture surface. The material removal behavior can be monitored with acoustic emission signals, the original signal, frequency domain and wavelet decomposition features were distinct attributed to the different material removal modes. Besides, low-scale subsurface damage also occurred at the parameters of small size grits and minimal grinding depth.