A cutting force model based on kinematics analysis for C/SiC in rotary ultrasonic face machining

Ceramic matrix composites (CMC) have superior properties and are used in the harsh conditions of high temperature and pressure, in aerospace, and other industries. However, due to inhomogeneous and anisotropic properties of the composites, the machining is still challenging to achieve desired efficiency and quality. For advanced materials, rotary ultrasonic machining is considered as a process with high-efficiency technology. The cutting force is a critical factor required to be effectively predicted and controlled to reduce processing defects in composites. In this research, the rotary ultrasonic machining was used for face machining (RUFM) of carbon-reinforced silicon carbide matrix composites (C/SiC), with a conical shaped tool. The kinematics between individual diamond abrasive and the workpiece material was analyzed to illustrate the separation characteristics in the cutting area. The condition for the intermittent machining during RUFM was obtained by establishing the mathematical relation between cutting parameters and vibration parameters. The indentation fracture theory was adopted to calculate the penetration depth into the workpiece by diamond abrasives in the RUFM. And then, the cutting force model was developed based on kinematics analysis in the RUFM of C/SiC. The relationship of cutting force and processing parameters including spindle speed, feed rate, cutting depth, and ultrasonic vibration amplitude were investigated. The comparison of the experimental and simulation data of the cutting force showed that for most of the tests, the errors were below 15%. Therefore, the cutting force model developed in this paper can be applied to predict cutting forces and optimize the process in the RUFM of C/SiC.