Kinematic Analysis of Ultrasonic Vibration Grinding Cf/SiC Composites and  Performance Evaluation

In the precision machining of carbon fiber reinforced silicon carbide ceramic matrix composites (C _f /SiC), grinding constitutes a critical process for achieving high surface quality and dimensional accuracy. However, the material's pronounced hard and brittle nature induces substantial mechanical cutting stresses during conventional grinding, leading to aggravated grinding wheel wear and workpiece surface damage—key process bottlenecks. Ultrasonic vibration grinding (UVG) leverages its unique high-frequency intermittent loading characteristics to provide an innovative solution for regulating the removal process of heterogeneous composites. This study establishes a logical framework encompassing "ultrasonic-enhanced grinding mechanism analysis, ultrasonic vibration kinematics analysis, experimental design, and performance evaluation." First, the ultrasonic-enhanced grinding mechanism is elucidated. Subsequently, the influence mechanism of ultrasonic vibration kinematics is revealed. Performance evaluation experiments for ultrasonic grinding of C _f /SiC are designed, clarifying how ultrasonic vibration optimizes abrasive grain trajectories to influence grinding forces and surface quality. Comparative experiments demonstrate that under unchanged grinding parameters, adding ultrasonic vibration reduces the normal grinding force from 19.32 N to 13.41 N (a 30.59% reduction) and the tangential grinding force from 15.46 N to 10.31 N (a 33.31% reduction). Through single-factor experiments, it is verified that increasing ultrasonic frequency and amplitude optimizes the grinding process, reduces surface roughness, and thereby enhances machining quality and surface integrity. An orthogonal experiment for ultrasonic grinding of C _f /SiC composites is designed. Using signal-to-noise (S/N) ratio analysis and analysis of variance (ANOVA), the optimal parameter combination is identified as: ultrasonic amplitude of 8 µm, ultrasonic frequency of 20,000 Hz, spindle speed of 24,000 rpm, feed rate of 80 mm/min, and grinding depth of 75 µm, achieving the optimal UVG application effect.