Effect of interface microstructure on properties of TiCx/Cu composites synthesized by dissolving graphite particles in Cu-Ti melt

Abstract

An approach for synthesizing TiC_x/Cu composites by dissolving graphite particles in a Cu-Ti alloy melt was investigated. The resulting TiC_x/Cu interface exhibited a distinctive "Cu-interface transition layer-TiC_x" sandwich-like structure. Results show that the initial Ti content (W_Ti) in the melt determines the stoichiometry of TiC_x within the matrix. Additionally, the interface transition layer, consisting of Cu, Ti, and C atoms, was shown to enhance the bonding strength between the reinforcement phase and the matrix. DFT calculations revealed that charge transfer between the transition layer and the Cu matrix (TiCu_yC_x/Cu) is greater than that between TiC_x and the Cu matrix (TiC_x/Cu). The formation of Cu-Cu metal bonds between the transition layer and the Cu matrix enhances the interface bonding, resulting in a more cohesive interface. Therefore, the TiC_x/Cu composite with a 30% volume fraction of Ti_xC prepared in this study has achieved a flexural strength of 1000 MPa. This proposed method significantly improves the mechanical properties of TiC_x/Cu composites and offers a promising, cost-effective approach for producing ceramic/metal composites with strong interface microstructures and superior bonding strength.