基于非均匀构型设计的高性能(Ni2B+C)/Cu复合材料及其载流摩擦磨损机理研究

在高速铁路、高灵敏度雷达等为代表的中国制造标志性产业中，移动电接触部件的国产化迫切需要自主研发兼具高强度、高导电和高耐磨的新型铜基材料。为协调导电性与强度和耐磨性的矛盾，本项目改变增强相均匀分布的常规设计思路，在原位同步生成增强相和自润滑相的新型Cu-Ni-B4C复合材料体系的基础上，提出将增强相集中在带状区进行非均匀构型的新思路。系统研究增强相不均匀程度对强度和导电性的影响，阐明非均匀构型(Ni2B+C)/Cu复合材料的强化与导电机理；探究机械摩擦、热效应和电弧烧蚀的耦合作用及Ni2B和C的转移与晶化行为，揭示复合材料的载流摩擦磨损机理。在解决这两方面关键科学问题的基础上，通过成分与工艺设计实现不均匀构型调控，制备出高强高导和高耐磨协调统一的非均匀构型(Ni2B+C)/Cu复合材料，为解决国家重大装备核心部件对特殊材料的需求及材料和摩擦学研究的关键共性问题提供理论指导与技术支撑。

With the rapid development of high-speed railway, high-precision radar and other typical made-in-china products, the urgent demands of high strength, high electrical conductivity and high wear resistance on copper materials are put forward for the key moving electric contact parts. To achieve high strength and excellent electrical conductivity, a nonuniform architecture, viz. the reinforcements concentrating on banding zones rather than uniform distribution, is constructed in a novel Cu matrix composites system Cu-Ni-B4C. Apart from the good combination of high strength and high electrical conductivity, high wear resistance can also be achieved based on Cu-Ni-B4C system due to the simultaneous formation of reinforcement and lubricating phase (Ni2B+C) via the in-situ reaction between Ni and B4C. In such a project, the influence of the nonuniform degree of reinforcements, namely the size and amount of the banding zones along with the size and amount of reinforcements inside them, on the strength and electrical conductivity is firstly studied, and then the strengthening and conducting mechanisms of (Ni2B+C)/Cu composites are clarified. Subsequently, the coupling effect of the mechanical friction, heat effect and arc erosion together with the transferring and crystallizing behavior of Ni2B and amorphous C are investigated, and then the friction and wear mechanism of (Ni2B+C)/Cu composites with electrical current is disclosed. Based on the solving of the above two key scientific problems, the nonuniform architecture can be regulated by optimizing the chemical composition and processing parameters, and the (Ni2B+C)/Cu composites with an.excellent combination of strength, electrical and wear resistance can be prepared. The results of this project can provide theoretical guidance and technical support not only for the special material requirements in the core components of national major equipment, but also for the key generic issues in the fields of material science and tribology.