镀镍石墨粉对铜基石墨复合材料力学性能的影响

Effect of graphite coated with nickel on mechanical properties of copper-matrix/graphite composite materials

采用粉末冶金工艺制备铜基石墨复合材料，考察烧结工艺、石墨粉颗粒表面镀镍及强化相对铜基石墨复合材料的力学性能和组织结构的影响，并对材料的组分、显微组织形态结构及断口形貌等进行系统的观察和分析，测试材料的硬度、冲击韧性和在室温、300℃、500℃各温度的压溃强度。结果表明：采用镀镍石墨粉改善了石墨和铜合金基体界面结合状态，界面结合更加牢固紧密，明显提高铜基石墨复合材料的力学性能，室温压溃强度和冲击韧性提高了30％～50％，高温强度提高了35％～60％，而对复合材料的硬度影响不大，复压复烧工艺更有利于发挥镀镍石墨粉的优越性。

The copper-matrix/graphite composite materials were prepared by powder metallurgy method. The influence of sintering process, graphite coated with nickel and reinforcement on mechanical properties and microstructure of the composites was investigated. The composition, microstructure and fracture morphology of the composites were observed and analyzed systematically. The hardness and impact toughness of the composites were measured, and the disruption strength at room temperature, 300℃ and 500℃ of the composites were tested, too. The results show that graphite particles coated with nickel greatly improve the interfacial combination between graphite and copper-matrix and remarkably increase the mechanical properties of the composites, the strength and toughness of the composites at room temperature increase by 30%-50%, the high temperature strength of the composites increase by 35%-60%, but there is little influence on the hardness of the composites. The coated graphite shows the superiority performance through the repressing and resintering process.