Grinding characteristics during ultrasonic vibration assisted grinding of alumina ceramic in selected dry and MQL conditions

Abstract

Abstract Ultrasonic vibration assisted grinding (UAG) has proven to lower the forces and improve the ground surface quality while shaping difficult to grind materials such as ceramics. A systematic study of UAG of alumina ceramic using a metal bonded diamond grinding wheel has been performed here. Taguchi’s L18 array based experimentation has been performed to study the effect of UAG parameters. During UAG, the vibration amplitudes of 6 and 12 microns have been used and the frequency has been kept at 20 kHz. From these experiments, optimum parameters for UAG have been identified using Grey relational analysis. Mathematical models generated using regression analysis have been found to correlate the experimental data with good accuracy. A comparison of the grinding forces and roughness of the surfaces generated in dry and minimum quantity lubrication (MQL) conditions in both conventional grinding and optimal condition in UAG has been performed to identify the beneficial effects of providing vibration to the workpiece. The surface quality has been evaluated using 3D roughness data, 3D plots and SEM images of the ground surface. By examining nature of the ground surface and kurtosis (Sku) values of the surface profile, it has been concluded that UAG reduces brittle fracture and facilitates material removal by ductile mode for alumina. The desired condition of least machining forces and highest surface quality has been achieved during the combination of UAG and MQL.