Fabrication, microstructure and mechanical properties of carbon fibers reinforced aluminum matrix composites with various metal coatings

This study employed an electroless plating process to apply copper and nickel coatings onto carbon fibers (CF), respectively. Using rapid hot-press sintering, copper-coated carbon fiber-reinforced aluminum matrix composites (Cu@CF/Al) and nickel-coated carbon fiber-reinforced aluminum matrix composites (Ni@CF/Al) were fabricated. A systematic investigation was conducted on how the type of coating metal affects the microstructure and mechanical properties of the composites. The experimental results demonstrated that Cu@CF/Al exhibited superior thermal stability at high temperatures in comparison to Ni@CF/Al. This is ascribed to significant interdiffusion between the Ni – P coating and the carbon fiber at high sintering temperatures, which degraded the internal structure of the fiber, whereas the copper coating effectively preserved the structural integrity of the carbon fibers. Among the four composites, Cu@CF/Al achieved the highest tensile strength and Brinell hardness, measuring 282 MPa and 56 HB, respectively, representing an 86% increase in tensile strength and a 43% improvement in hardness over pure aluminum, while maintaining an elongation of 12%.