Promoted SiC particle fracturing-based surface smoothing of SiCp/Al composites by in-situ laser-assisted diamond turning

Abstract

While the machined surface integrity of SiCp/Al composites is closely linked to the damage behavior of SiC particles, tailoring the fracture behavior of SiC particles is crucial for promoting the machinability of SiCp/Al composites. This study proposes a viable strategy based on the in-situ laser-assisted diamond turning (in-situ LAT) to enhance the machinability of SiCp/Al by promoting particle fracture through thermal softening. Specifically, end-face diamond turning experiments of 45 vol% SiCp/Al using a customized in-situ LAT system reveal significant improvements in the cutting performance over conventional turning, including a 48.1 % reduction in surface roughness and a 29.4 % decrease in cutting force. A finite element model incorporating temperature-dependent thermophysical constitutive properties of Al, SiC, as well as Al-SiC interface, is developed to investigate the on-going in-situ LAT process. Combined with experimental observations, the simulation results demonstrate that thermal softening promotes a fracture-dominated mechanism in SiC particles, leading to superior surface integrity compared to the crushing behavior observed in conventional turning. This work offers both mechanistic insights and practical approach for improving the machining performance of particle-reinforced metal matrix composites.