Multi-phase modeling of SiC particle removal mechanism in ultrasonic vibration–assisted scratching of SiCp/Al composites

A micromechanics model based on multi-phase modeling was established by using ABAQUS software. The material removal mechanism of SiC particle and the interactions among the cutting tool, SiC particle, Al matrix, and interface were studied, and the simulation results were compared to the experimental results. Different relative positions between the cutting tool and SiC particles can lead to different removal modes of SiC particles, including rolled or penetrated in Al matrix mode, fractured mode, and pulled out mode. Among them, fractured mode can be further divided into partial fractured mode and complete fractured mode. In complete fractured mode and pulled out mode, the SiC particle and its surrounding interface are seriously destroyed. Therefore, in the actual machining process, a small value of cutting depth should be chosen to make the SiC particle removed in rolled or penetrated in Al matrix mode or partial fractured mode for a better structural integrity of SiCp/Al composites. The pit as a result of SiC particle fractured and pulled out from Al matrix is the main defect on the machined surface. With the assistance of ultrasonic vibration, friction coefficient between the cutting tool and workpiece can be decreased. Thus, a better surface integrity of SiCp/Al composites can be obtained. The simulation results agree well with the experimental results.