Reaction Mechanisms And Mechanical Properties Of The In-situ Copper Matrix Composites Reinforced By TiC Particles From (Al-)Ti-C-Cu System

In this paper, heat diffusion method (XD) was used to fabricate TiC particulate reinforced copper matrix composites through in-situ reaction method successfully from Al-Ti-C-Cu and Ti-C-Cu system as raw materials. The reaction thermodynamics of the Al-Ti-C-Cu and Ti-C-Cu system were calculated, and the SEM observation and EDS spectrum of the reaction products were analyzed, the phase composition of reaction products were identified combining with XRD, the reaction process model were built to explore the reaction mechanism.The Al-Ti-C-Cu and Ti-C-Cu system reacted in accordance with the reaction thermodynamics, and generate the TiC particle reinforced phase respectively, particle reinforced copper matrix composites were prepared. Studies have shown that the reactions in Al-Ti-C-Cu system during sintering process could be devided in three phases. Phases were Cu+Alâ†'G.P.(â… )â†'G.P.(â…¡)â†'CuAl2(θ"), CuAl2(θ")â†'CuAl2(θ")â†'CuAl2(θ) and Al+Tiâ†'Al3Ti, Ti+Câ†'TiC and Al+Tiâ†'Al3Ti. The apparent activation energy of each reaction phase were 345.00kJ·mol-1,175.58kJ·mol-1,1893.37kJ·mol-1, when volume fraction of reinforcement was 20%. The apparent activation energy of each reaction phase were 935.75kJ·mol-1, 783.07kJ·mol-1, 1581.58kJ·mol-1, when volume fraction of reinforcement was 30%. Reactions in Ti-C-Cu system during sintering process was only one phase. The apparent activation energy the phase was 2642.62kJ·mol-1, when volume fraction of reinforcement was 20%. The apparent activation energy the phase was 1943.55 kJ·mol-1, when volume fraction of reinforcement was 30%.The research of performance testing showed that:At the same conditions, the Vickers hardness of the copper was 78.8HV, while the elongation rate was 19.60%. The tensile strength of the copper was 161.29MPa. When the reinforcement volume fraction of the Al-Ti-C-Cu and Ti-C-Cu systems was 30%, the hardness of Vivtorinox were 180.1HV and 96.2HV, while the elongation rate were 2.73% and 1.57%. The tensile strength of the composites were 317.44MPa and 226.58MPa. Tensile fracture surface observed by means of the SEM, the fractures of Al-Ti-C-Cu and Ti-C-Cu systems showed a fiber fracture morphology and a pit which have the smooth bottom.