Study on the scratching force surface damage morphology of SiCf/SiC composites by single abrasive grain with ultrasonic assistance

Abstract

Continuous silicon carbide fiber reinforced silicon carbide matrix composites (SiCf/SiC) are used in many different industries,including aerospace, due to their high hardness, high temperature, and resistance to oxidation, corrosion, and wear. However,when machining SiCf/SiC composites, problems such as matrix rupture, edge chipping, fiber warping and pull-out, and toolwear are prone to occur. This paper conducts a finite element scratching simulation study on SiCf/SiC composites, which isvalidated through experiments to investigate the matrix and fiber damage destruction mechanism and to meet the demandfor high-quality, high-efficiency machining of SiCf/SiC composite structural components. Findings indicate that the scratchingforce increases with scratching speed, scratching depth, and ultrasonic amplitude increase. However, with the rise of thescratching angle, the scratching force tends to increase and then decrease. In addition, single-particle scratching experimentsshowed that matrix fragmentation, fiber breakage, fiber debonding and detachment, and matrix debonding between fiberswere the primary manifestations of SiCf/SiC composite damage. In the case of ultrasonic vibration scratching, the scratchmorphology is high-frequency impact scratches, and the vertical fiber fracture is neat. These findings clarify the fundamentaldamage and removal mechanisms of SiCf/SiC composites and provide a useful reference for optimizing machining parametersto enhance processing quality and efficiency.