Inhibition of interfacial reaction and enhancement of mechanical properties of CF/Al composite

The properties of carbon fiber-reinforced aluminum matrix (CF/Al) composite for aerospace applications are often limited by interfacial reactions. In this study, chemical vapor deposition (CVD) was applied to prepare pyrolytic carbon (PyC) coatings with different thicknesses on CF surfaces to reduce the C/Al interfacial reaction and improve the mechanical properties. Liquid-solid infiltration extrusion (LSIE) was used to prepare CF@PyC/ Al composite, and the effects of coating thickness on the interfacial microstructure, tensile properties and fracture behavior were investigated. The experimental results showed that the PyC coating enhanced the oxidation resistance of CF, but the toughness and tensile strength of the CF decreased. The coating effectively suppressed the generation of Al4C3 and provided a better quality interface for the composite. Compared with the uncoated CF/Al composite, the tensile strength of the CF@PyC/Al composite was enhanced by 35% at a coating thickness of about 0.23 mu m. In addition, the strength and modulus of the coated material behaved more stably at different layup angles, whereas the uncoated material was more sensitive to angle changes. These performance enhancements are mainly attributed to the effective hindrance of Al4C3 production by the coating, which enhances the crack deflection frequency and enhances the energy absorption capacity.