Effect of SiC nanowires addition on the interfacial microstructure and mechanical properties of the Cf-SiCNWs/AZ91D composite

Abstract

In the present study, carbon fibers grafted with SiC nanowires (Cf-SiCNWs) reinforced AZ91D composite (Cf-SiCNWs/AZ91D) was prepared by liquid-solid extrusion following vacuum infiltration (LSEVI) process. The effect of SiC nanowires (SiCNWs) on the interfacial microstructure, tensile properties and fracture behavior of the Cf-SiCNWs/AZ91D composite were investigated. First, the microstructure and fracture surface of the composite were characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The results showed that after introducing SiCNWs, the antioxidation of carbon fiber could be reasonably improved, which provided a better interface of the Cf-SiCNWs/AZ91D composite by preventing the detrimental interfacial reaction product of Al4C3. Then, the average ultimate tensile strength of SiCNWs-Cf/AZ91D composite was compared with that of Cf/AZ91D composite. It was found that after grafting SiCNWs on the surface of carbon fibers, the strength increased from 269.7 MPa to 358.8 MPa, corresponding to an improvement of 33%. This increase was attributed to the improved interface that took advantages of the superior mechanical properties of SiCNWs.