Direct Fabrication of Continuous Carbon Fiber-Reinforced Aluminum Matrix Composites via Ultrasonic Consolidation

Continuous carbon fiber-reinforced aluminum matrix (Cf/Al) composites offer excellent mechanical properties but face fabrication challenges due to poor wettability and the formation of brittle Al4C3 at high temperatures. Ultrasonic consolidation (UC) enables low-temperature solid-state bonding, yet the brittle carbon fibers are susceptible to damage from high shear stresses during the process. In this study, a Ti protective coating was deposited on carbon fibers via electrodeposition, and Cf/Al composites were successfully fabricated using UC. The results showed that a uniform Ti-based coating was achieved at 5 mol/L TiCl3 for 5 min. During UC, the Ti-based coating protected the fibers by absorbing shear stress through plastic flow, although it was largely separated from the fiber surface and replaced by direct mechanical interlocking with the aluminum matrix. Tensile tests revealed that the Cf/Al composites achieved significant improvements in yield strength (14.4%), ultimate tensile strength (18.5%), and fracture strain (50.5%) compared to unreinforced aluminum. Fracture surface analysis confirmed uniform fiber distribution and pull-out features, indicating effective load transfer. This work demonstrates that UC combined with Ti-based coating is a promising approach for the direct, low-temperature fabrication of high-performance Cf/Al composites.