Abstract Agglomerated brittle graphite and discontinuous matrix have decreased mechanics and friction properties of natural graphite/copper (NG/Cu) composites prepared through spark plasma sintering (SPS) with the blending of graphite and electrolytic copper powder. In that case, microstructure, mechanics and friction properties of NG/Cu composites were compared with that of carbon particles/cooper (CPs/Cu) composites prepared via ball-milling and SPS. CPs/Cu composites had higher strength and excellent friction properties, due to the uniform distribution of high content CPs (~4 μm, with carbon fiber structure) in Cu matrix, and ~36.40% of low angle grain boundaries (LAGBs) of continuous Cu matrix with finest grain size (~0.90 μm). The effective fixation of CPs by higher strength Cu matrix, combined with the consistency of microregion performance came from high-density uniformly dispersed of the micron-sized CPs, which significantly reduced the friction coefficient of the C/Cu composites against the steel disc and improved the stability of friction performance. Even at 400 °C, the softening of the matrix was greatly weakened owing to the pinning effect of CPs with excellent antioxidant properties on grain boundaries, and CPs/Cu composites still maintain good friction properties.

中文翻译：

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碳类型和形貌对碳/铜复合材料微观结构和性能的影响

摘要 石墨和电解铜粉共混通过放电等离子烧结（SPS）制备的天然石墨/铜（NG/Cu）复合材料，团聚的脆性石墨和不连续基体降低了其力学性能和摩擦性能。在这种情况下，将 NG/Cu 复合材料的微观结构、力学和摩擦性能与通过球磨和 SPS 制备的碳颗粒/铜 (CPs/Cu) 复合材料进行了比较。CPs/Cu 复合材料具有更高的强度和优异的摩擦性能，这是由于高含量 CPs（~4 μm，具有碳纤维结构）在 Cu 基体中的均匀分布，以及~36.40% 的连续 Cu 的低角晶界（LAGBs）具有最细粒度 (~0.90 μm) 的基质。高强度铜基体有效固定CPs，结合微区性能的一致性，来自微米级CPs的高密度均匀分散，显着降低了C/Cu复合材料对钢盘的摩擦系数，提高了摩擦性能的稳定性。即使在 400 °C 时，由于具有优异抗氧化性能的 CPs 在晶界上的钉扎作用，基体的软化被大大削弱，CPs/Cu 复合材料仍保持良好的摩擦性能。