微波加压活化烧结C/Cu复合材料及界面行为研究

C/Cu composites material which is known as a kind of metal matrix composites,given its excellent electrical and thermal conductivity, higher strength, lowerthermal expansion coefficient and higher wear resistance, which is now widely application prospect in the fields of aerospace, electronic and electrical engineering. The performance of C/Cu composites depends mainly on the preparation method and the bonding properties of the C/Cu interface. The traditional preparation method is difficult to solve effectively. This project using preparation of graphite/copper composites and influence mechanism of material roperties, and C/Cu interfacial bondingmechanism study as the breakthrough point, utilizes microwave activated sintering technology to reparation graphite/copper composites. The exploration of the main factors which may have influence on the microstructure and properties of graphite/copper matrix composites is conducted on various aspects, such as microwave power density, microwave strength distribution, graphite content, graphite particle size, sintering temperature and sintering time. While another aim of this project is focused on the ascertainment of the dielectric properties of materials in microwave field. Solutions of key technical problems are explored as well, such as the improvement of the wettability of graphite surface and the enhancement uniform distribution of graphite in the copper matrix. Intense research is attempted to reveal the influence mechanism of microwave sintering on graphite/copper composites interfacial bonding, and the migration characteristics of the graphite in Cu matrix. And to form the technical prototype of microwave activated sintering graphite/copper composites material. The result of this research project is expected to provide new preparation process of high performance C/Cu composites material preparation, and promote the microwave sintering technology applications in the field of preparation metal based composite material.

碳/铜复合材料具有优良的导电导热性、较高的强度、低热膨胀系数和高耐磨性，在航空航天、电子电工等领域有着广泛的应用前景。碳/铜复合材料性能主要取决于制备方法和C/Cu界面键合性能，传统方法难以有效解决。本项目以石墨/铜复合材料的制备和材料性能的影响，以及C/Cu界面键合机理研究为切入点，利用微波加压活化烧结技术制备石墨/铜复合材料。探索微波功率密度、微波场强分布、石墨含量、烧结温度和时间等主要因素对石墨/铜复合材料微观结构及材料性能的影响，测定物料在微波场中的介电特性，解决铜基体中石墨的均匀分布、铜对石墨的润湿性等关键技术问题，揭示微波作用下烧结工艺对石墨/铜复合材料界面结合的影响，以及石墨在铜基体中的扩散迁移特性，形成微波活化烧结石墨/铜复合材料技术原型。本项目的研究成果有望提供高性能碳/铜基复合材料制备新工艺，扩展微波烧结技术在金属基复合材料制备领域新应用。

碳/铜复合材料具有优良的导电导热性和高耐磨性，在航空航天、电子电工等领域有着广泛的应用前景。本项目以石墨/铜复合材料制备和材料性能影响，以及C/Cu界面键合机制为研究切入点，采用微波加压活化烧结技术制备石墨/铜复合材料。结果表明微波烧结石墨铜复合材料在组织结构、物理机械性能等方面优于常规烧结，微波烧结速度快、时间短，有利于铜基体晶粒细化，对碳/铜界面焊合、材料致密化及性能提升具有明显的作用。探究了金属钛、二硫化钼等组元对石墨/铜复合材料烧结性能的影响，以及石墨/铜界面特征、活化金属分布、碳化物过渡层变化、铜基体晶粒组织变化等。微波有利于促进活化金属在铜基体中的扩散，提高复合材料性能。添加Ti元素将在石墨/铜界面生成TiC过渡层，有效提升复合材料的相对密度、硬度和导热系数，当Ti添加量为1.0wt%时，微波烧结样品的相对密度和导热系数分别为94.7%和416.23(W/m·K)，导热系数较常规烧结提升了78.2%；添加1.5%二硫化钼时铜基体平均晶粒尺寸仅为1.47μm，在200℃高温条件下表现出较好的耐磨性能；此外，石墨表面化学镀铜有利于碳/铜界面润湿，改善铜与石墨的界面结合，材料的相对密度达98%以上，导热系数为489.57(W/m·K)。微波加压烧结有利于减小C/Cu界面间隙，降低孔隙率，提高复合材料物理机械性能，且随着石墨粒径的增大，热导率显著提升，当石墨粒径为300μm，体积分数50%时，在0.2MPa压应力下复合材料导热系数可达680(W/m·K)，表现出优异的导热及摩擦性能。针对石墨与膨胀石墨、碳纤维及金刚石等碳基复合材料制备开发表面改性新技术，开发了微波高通量烧结装置及技术，可拓展至粉末冶金烧结、合金熔炼等相关领域，对有色金属材料制备及性能提升具有实际意义。.项目执行过程发表学术论文9篇，其中SCI收录论文8篇，EI论文1篇；授权国家发明专利6件，美国发明专利1件；获中国产学研合作创新成果二等奖1项；项目负责人入选“长江学者奖励计划”青年学者、云南省中青年学术和技术带头人等，达到了项目的预期目标。