Investigation on the cutting mechanism of SiCp/Al composites in ultrasonic elliptical vibration machining

Abstract

Aluminum (Al)-based silicon carbide (SiC) material composites are considered as difficult-to-machine materials because of the presence of hard reinforced SiC particles, which results in a greater cutting force and poor surface integrity during the machining process. This paper established micro-anisotropic material mechanical models of SiCp/Al composites with a 10vol% SiC particles, and studied the difference in the machining mechanism between ultrasonic elliptical vibration cutting (UEVC) and ordinary cutting (OC) about SiCp/Al. Moreover, this paper mainly focuses on the influence of UEVC on cutting force, von Mises stress distribution, surface integrity, and chip formation. The models are validated by comparing cutting force, chip shapes, and machined surface features in OC machining SiCp/Al experience from the literature. Simulation results indicate that the cutting mechanism of SiCp/Al on UEVC is different from that of OC and has several good properties. At the same cutting parameters, high-frequency vibration makes the cutting force of UEVC exhibit variable periodicity and reduces average cutting force. The instantaneous impact of tool and fast separation results in a more concentrated von Mises stress distribution, thereby resulting in the particles having a greater break degree than that obtained with OC. A comparison of the surface roughness values from the simulation result shows that UEVC obtains better surface integrity than OC does.