Experimental and simulation analysis of surface morphology characteristics through multiple methods of ultrasonic vibration-assisted grinding using a single grain

Abstract

The high hardness and brittleness of silicon carbide (SiC) ceramics lead to issues such as low efficiency and severe surface damage during the machining process. Ultrasonic vibration-assisted grinding (UVAG) is an important means to efficiently machining this kind of material, but the surface quality obtained by different vibration modes varies. In order to investigate the scratch morphology characteristics and formation mechanisms by one-dimensional, two-dimensional and three-dimensional UVAG, this article conducted simulation and experimental studies on conventional grinding (CG), axial ultrasonic vibration-assisted grinding (AUVAG), elliptic ultrasonic vibration-assisted grinding (EUVAG) and composite ultrasonic vibration-assisted grinding (CUVAG) of SiC ceramics. The scratch morphology characteristics, the scratch width ratio, the grinding forces and the distribution of residual stress in the four grinding modes were analyzed using a single grain. The results show that the fractures are more pronounced on the scratch sides created by CG and AUVAG, with poor morphology at the scratch bottom. But good morphologies at the scratch bottom in forms of small facets are acquired by EUVAG and CUVAG. The scratch width ratio increases in sequence of CG, AUVAG, EUVAFG and CUVAG, indicating that UAVG can effectively improve the material removal efficiency. Compared to CG, UVAG has a maximum reduction of 67.5 % in grinding force. Meanwhile, as the axial amplitude increases, the grinding forces of AUVAG and CUVAG first decrease and then increase; as the elliptic amplitude increases, the grinding forces of EUVAG and CUVAG slowly increases. In addition, the maximum residual stress of CG, AUVAG, CUVAG and EUVAG is decreased in sequence. EUVAG and CUVAG show lower and more evenly distributed residual stresses at the bottom of the scratch, which indicates that elliptic ultrasonic vibration can significantly improve surface quality and reduce residual stress. EUVAG performs best in improving the surface finish, while CUVAG strikes a good balance between high efficiency and low damage.