Study on the removal behavior of constituent phases of SiCp/Al composites by ultrasonic vibration-assisted milling

SiCp/Al composites are widely used in aerospace, optical devices, electronic devices and other fields due to their excellent properties such as wear resistance, high specific strength and low thermal expansion coefficient. Due to the difference between the constituent phases of SiCp/Al composites and the high hardness of SiC particles, conventional milling (CM) leads to problems such as poor processing quality and severe tool wear. Ultrasonic vibration-assisted milling (UVAM) can achieve high-quality cutting of SiCp/Al composites. However, the relationship between constituent phases (SiC particles, Al matrix) and tool under ultrasonic vibration is complex and the research depth is insufficient. This paper focuses on the study of the interaction between the constituent phase of SiCp/Al composites and the tool in UVAM. The formation process of residual cutting zone and material removal mechanism in ultrasonic machining were analyzed, and the influence of ultrasonic vibration on the removal mechanism of SiCp/Al composites was explored from the aspects of tool cutting speed and tool kinetic energy. A three-dimensional micro-cutting model of SiCp/Al composite multi-particles was established, and the interaction between constituent phases and tool during cutting under different ultrasonic amplitude conditions was analyzed by finite element method and combined with a series of experiments. The results show that the introduced ultrasonic vibration increases the kinetic energy of the tool and improves the tool's ability to damage SiC particles and Al matrix. Compared with CM, UVAM significantly reduces surface pits, scratches, and SiC particle crushing defects, and the surface roughness Sa is reduced by 32.33 %. Tool wear is relieved, and the wear of the back tool face is reduced by 22.31 % at most. At the same time, the resultant milling force is also decreased 32.76 %. In short, the research in this paper is of great significance to improving the high-quality processing of SiCp/Al composites.