石墨烯负载铜增强铜基块体复合材料的制备及其性能

石墨烯具有独特的二维结构及性能已成为金属基复合材料制备过程中理想的增强相备选材料之一。而铜因具有良好的导热性、导电性和化学稳定性已被广泛应用到电子产品中，但其存在机械强度低、硬度低等缺点成为其应用亟需解决的瓶颈问题。目前，将石墨烯和铜基材料进行结合，虽然在一定程度上可以改善铜基材料的的综合性能。但由于石墨烯易产生团聚，石墨烯与铜之间的润湿性差，使其两者难以形成良好的界面结合，进而导致复合材料的性能变差。因此，为了解决上述问题，本文通过化学还原法在石墨烯上负载铜粒子对石墨烯进行改性处理，成功制备了石墨烯负载铜复合粉体(Cu-rGO)，并将其作为增强相，与纳米铜粉混合，运用放电等离子烧结(SPS)工艺制备了石墨烯负载铜增强铜基块体复合材料(Cu-rGO/Cu)，研究Cu-rGO复合粉体含量对铜基体组织和性能的影响。研究发现，在50 mg氧化石墨烯(GO)和200 mg硫酸铜(CuSO4·5H2O)时，获得Cu-rGO复合粉体中还原氧化石墨烯较薄且分布均匀。同时结合TEM结构分析发现铜基体与增强相接触界面紧密，且增强相的引入可以有效地细化块体复合材料的晶粒。另外，随着增强相含量的递增，硬度呈...

Preparation and properties of graphene-supported copper reinforced copper matrix bulk composites

Graphene has a unique two-dimensional structure and properties, which has become one of the ideal reinforcement phase candidates in the preparation of metal matrix composites. Copper has been widely used in electronic products because of its good thermal conductivity, electrical conductivity and chemical stability. But its shortcomings, such as low mechanical strength and low hardness have become a bottleneck problem that need to be solved urgently. At present, the combination of graphene and copper can improve the comprehensive properties of copper matrix materials to a certain extent. However, because graphene is easy to agglomerate and the wettability between graphene and copper is poor, it is difficult to form a good interface between graphene and copper, which leads to the deterioration of the properties of the composites. Therefore, in order to solve the above problem, by chemical reduction method, graphene was modified by reinforcing copper particles on graphene. Finally, the graphene-supported copper composite powder (Cu-rGO) was successfully prepared. Then it was selected the reinforcement phase and mixed with nano-copper powder, and the graphene-supported copper reinforced Cu matrix bulk composite materials (Cu-rGO/Cu) was prepared by the spark plasma sintering (SPS). The effect of the graphene-supported copper composite powder content on the microstructure and properties of copper matrix was studied. The results show that the reduced graphene oxide in the obtained graphene-supported copper composite powder is relatively thin and uniformly distributed with the mass of GO about 50 mg and CuSO₄·5H₂O about 200 mg. Meanwhile, combined with the TEM structure analysis, it is observed that the contact interface between the copper matrix and the reinforcing phase is close, and the introduction of the reinforcing phase can effectively refine the crystal grains of the bulk composite material. In addition, with the increase of the content of reinforced phase, the hardness first increases and then decreases. Especially, when the content is 2wt%, the hardness increases by 17.6%. However, its conductivity and density show a downward trend, which is due to that the oxygen-containing functional groups in the graphene oxide are not completely reduced during the reduction process, and it may be due to the occurrence of defects and agglomeration of the graphene.