A novel low-damage and low-abrasive wear processing method of Cf/SiC ceramic matrix composites: Laser-induced ablation-assisted grinding

Continuous fiber-reinforced ceramic matrix composites are promising materials for advanced hot end components and safety-critical components of aeronautics and astronautics; however, the difficult-to-process problem of these materials has been one of the technical bottlenecks restricting their high-performance service. The present work proposed a novel high-efficiency, low-damage, and low-abrasive wear processing method based on the chemical properties of the materials, which used lasers to ablate workpieces before grinding-laser-induced ablation-assisted grinding (LIAAG). The material removal mechanism of Cf/SiC composites was investigated by single-grain scratching tests; the grinding performances of LIAAG in terms of grinding force, grinding temperature, surface integrity, abrasive wear, grinding chips were evaluated by a contrast abrasive belt grinding test. It was found that Cf/SiC composites were chemically transformed into relatively loose and homogeneous ablation products (SiO2 and recrystallized SiC) at high laser ablation temperatures, which were easier to remove during grinding. In this case, surface morphologies displayed the microfracture and crushing of carbon fibers and SiC matrixes, and the grinding-induced damages, such as macro fracture, fiber pull-out, interface debonding, were significantly contained. Abrasive belt was primarily worn in micro-adhesion and micro-abrasion, rather than cleavage fracture and the fall-off in traditional grinding. Under optimum parameters, the grinding force, grinding temperature, and average surface roughness of belt grinding were reduced by 47 %, 40 %, and 26 %, respectively. Consequently, the surface integrity was improved greatly, and the abrasive wear was reduced significantly. The work provides a vital high-performance processing method for ceramic matrix composites components.