Experimental investigation on subsurface damage characteristics in ultrasonic-assisted grinding of silicon carbide

In this study, systematic multi-step two-dimensional ultrasonic-assisted grinding (2DUAG) experiments are performed to reveal the influences of processing parameters on the subsurface damage (SSD) depth and characteristics of silicon carbide (SiC). The experimental findings demonstrate that in rough and semi-finishing machining stages, the SSD mainly contains median cracks, lateral cracks, localized material crushing, material peeling, and damage regions caused by the growth of brittle cracks to material defects. In finishing machining step, the SSD is characterized by small-size material peeling and localized crushing. Meanwhile, the SSD depth presents a downward tendency as the tool vibration amplitude (TVA) increases, with maximum reductions of 24.13%, 39.29% and 26.49% in three machining steps, respectively. In rough machining stage, the workpiece vibration amplitude (WVA) and TVA have similar influences on that. While in semi-finishing stage and finishing stage, the SSD depth decreases first and then grows as the WVA increases from 0 μm to 8 μm with an inflection point appearing around 4 μm.