Investigation on machining mechanism and surface integrity of Sip/Al composites with ultrasonic vibration-assisted epoxy coating cutting

Abstract

Due to the significant mechanical differences between the plastic Al matrix and the brittle Si particles, the ultra-precision machining of Sip/Al composites is considered a major challenge. To overcome this challenge, this paper proposes a new cutting strategy, namely ultrasonic vibration-assisted epoxy coating cutting (UV-ECC). By analyzing the groove morphology, cutting force, chip morphology, residual stress, and surface roughness, the effect of UV-ECC on the machining mechanism and surface integrity of Sip/Al composites is investigated. Research results indicate that epoxy coating can provide compressive stress to the surface of Sip/Al composites, thereby suppressing the formation and propagation of cracks as well as the pull-out or rotation of particles. After the introduction of ultrasonic vibration, the vibrating tool can compensate for the shortcomings of the epoxy coating in terms of chip removal. Furthermore, the intermittent separation reduces the damage to both the Sip/Al composites and the epoxy coating. Finally, the space gap created by the elliptical trajectory allows the crack suppression effect of the epoxy coating to be seen as a significant improvement. Overall, compared to traditional cutting and epoxy coating cutting, UV-ECC offers significant advantages in enhancing surface integrity, reducing specific cutting force, and achieving a uniform residual stress distribution. Among them, the surface roughness decreased by 75.4 % and 59.0 %, respectively, and the specific cutting force decreased by 75.01 % and 64.89 %, respectively. The current research provides a promising cutting strategy for achieving efficient and low-damage machining of Sip/Al composites.