Interface engineering in CF/Al matrix composites for enhancement in mechanical strength and anti-corrosion properties

Metal matrix composites (MMCs), renowned for their lightweight and exceptional mechanical properties, are currently in high demand. Herein, carbon fiber‑aluminum metal matrix composites (CF/Al MMCs) modified with 4 types of corrosion-barrier interface coatings (CBCs), respectively, including Ni, TiO₂, ZnO, and Al₂O₃ were investigated, and the composites were prepared by squeeze casting technique. The effects of these CBCs on the CF/Al interface reaction and the mechanical properties and electrochemical corrosion resistance of the composites are revealed and discussed thoroughly. It is observed that T300‑carbon fiber reinforced MMCs without any CBCs exhibit low mechanical strength due to the formation of Al₄C₃ phase induced by strong interaction between fiber and matrix. With CBCs, the formation of Al₄C₃ was significantly suppressed. Comparatively, the ZnO-coated CF/Al MMCs exhibit the most remarkable enhancement in the mechanical properties with a flexural strength of 796.4 MPa and a modulus of 105.3 GPa, which are approximately 114% and 52.2% higher than those of the counterparts without CBCs, respectively. More importantly, the CF/Al MMCs with CBCs demonstrate superior chemical corrosion resistance, retaining their mechanical performance even after a 7-day immersion in salt solutions. These results provide an important guideline in interface engineering for MMCs with enhanced mechanical properties and electrochemical corrosion resistance.