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Copper-graphite composites find extensive application as electrical contact materials. However, their tribological properties are limited by the weak interfacial bonding. In this study, Ti 3 AlC 2 was used to modify copper-graphite composites fabricated by vacuum sintering. The incorporation of Ti 3 AlC 2 included both coated Cu and uncoated Cu. The hardness, relative density, tribological properties, and microstructure of the composites were thoroughly investigated. The results show that the addition of Ti 3 AlC 2 coated with Cu was conducive to avoiding the agglomeration of Ti 3 AlC 2 particles, and resulting in superior relative density, hardness, lubrication and wear resistance of the composites. Furthermore, the incorporation of Ti 3 AlC 2 not only enhanced the presence of lubricating components in copper-graphite composites but also improved the interface bonding strength between the copper matrix and graphite. Specifically, Cu-graphite-Ti 3 AlC 2 (Cu-coated) composites displayed a relative density of 92%, a hardness of 94.2 HV, a friction coefficient of 0.175, and a wear rate of 1.28 × 10−6 mm3/N·m. • Graphite and Ti 3 AlC 2 were used to synergistically reinforce copper matrix composites. • The microstructure and properties of Cu-graphite-Ti 3 AlC 2 composites were investigated. • The interfacial bonding between copper and graphite was improved. [ABSTRACT FROM AUTHOR]

Cu-graphite-Cr 3 C 2 composites were synthesized via spark plasma sintering (SPS) using different gas environments, including argon and air, to blend the raw materials consisting of Cr 2 AlC, Cu-coated graphite, and pure Cu. The microstructure and physical properties of the composites were thoroughly investigated. The findings revealed that Cr 3 C 2 , synthesized in situ from Cr 2 AlC, was firmly embedded in the Cu matrix. Additionally, a layer of Cr 3 C 2 was formed at the interface between the Cu matrix and graphite. The composites showed a high relative density, which above 96 %. The composites fabricated with the raw materials mixed in an argon gas environment had a hardness of 72.6 HSD and an electrical conductivity of 1.102 × 106 S·m−1. Whereas, the hardness and electrical conductivity of the composites fabricated with the raw materials mixed in an air gas environment increased to 75.6 HSD and 1.314 × 106 S·m−1, respectively. Furthermore, Cu-graphite-Cr 3 C 2 composites fabricated with the raw materials mixed in air rather than argon exhibited better lubrication performance and wear resistance, the average friction coefficient and wear rate were measured to be 0.4644 and 2.682 × 10−7 mm3/N·m, respectively. • Cu-graphite-Cr 3 C 2 composites were prepared with copper-coated graphite, copper and Cr 2 AlC. • Cr 3 C 2 was synthesized from Cr 2 AlC in situ. • The microstructure and properties of Cu-graphite-Cr 3 C 2 composites were investigated. • The composites samples were analyzed by XRD, SEM and EDS. [ABSTRACT FROM AUTHOR]

Copper/graphite/Ti 2 SnC composites were prepared using spark plasma sintering with copper-coated graphite powder, Ti 2 SnC powder, and copper powder as raw materials. The effect of sintering temperatures (800, 850, 900, and 950 °C) on the microstructure, relative density, hardness, resistivity, and tribological properties of the composites was studied in this paper. The results show that Cu and Ti 2 SnC demonstrate obvious inter-diffusion during sintering and become stronger with an increase in the sintering temperature, and the phase change process of the Cu matrix was in the order: Cu → Cu 5.6 Sn → Cu 41 Sn 11 → Cu 3 Sn. The relative density, hardness, friction coefficient, and the wear rate of the composites were the best when the sintering temperature was 900 °C, and their values were 97.21%, 67.68 HSD, 0.25, and 3.72 × 10−6 mm3/(N·m), respectively, whereas the resistivity of the composites was the best when the sintering temperature was 950 °C, and it was 6.116 × 10−7 Ω m. • Copper/Graphite/Ti 2 SnC composites were prepared by spark plasma sintering. • The composites samples were sintered at different temperatures (800, 850, 900, 950 °C). • The tribological properties, hardness, and resistivity of the composites samples were investigated. • The composites samples were analyzed by XRD, SEM, and EDS. [ABSTRACT FROM AUTHOR]