Modeling and experimental analysis of surface topography generation mechanism during ultrasonic vibration-assisted grinding

Abstract

Surface morphology is an important index to evaluate the grinding performance of grinding wheel, and abrasive grains and grinding fluid have a great influence on the formation of grinding surface. The abrasive grains used in actual grinding are irregular geometries, and the distribution on the grinding wheel is also irregular, which brings difficulties to the study of the surface topography. Based on the actual geometric shape of CBN abrasive grains, the corresponding geometric features are extracted and models of CBN abrasive grains are established in this paper. Under the premise of considering the randomness of the abrasive grains distribution and the material removal mechanism, the simulation of the grinding surface was carried out to predict the 3D surface topography. Through the established experimental platform, the related experiments of dry grinding and wet grinding of common grinding (CG) and ultrasonic vibration assisted grinding (UVAG) were carried out. The experimental results are in good agreement with the simulation results. In dry grinding experiments, tangential ultrasonic vibration-assisted grinding (TUVAG) produces groove-like ultrasonic vibration textures that facilitate material removal. Radial ultrasonic vibration-assisted grinding (RUVAG) has a large impact on the machined surface, and pits and a large number of micro-cracks appear, which effectively weakens the strength of the material. In wet grinding experiments, the grinding fluid effectively improves the working conditions of the grinding zone and obtains better surface quality. The surface roughness of TUVAG is the lowest under both dry grinding and wet grinding conditions. Under the condition of dry grinding, the surface roughness of RUVAG is better than that of CG. The opposite is true in wet grinding.