Guo Hai-Xia, Yang Jian-Feng
State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China.
Materials (Basel). 2020 Jan 18;13(2):463. doi: 10.3390/ma13020463.
Graphite-metal composites have been used as friction materials owing to their self-lubricity, which is ascribed to the weak interlayer bonding of graphite. To overcome the shortage of graphite flake (GrF)-filled composites of having low tribological properties, graphite-Cu composites with mesocarbon microbead (MCMB) as the solid lubricant are developed in this paper. The MCMB-Cu composites have a lower friction coefficient and wear rate than do the GrF-Cu composites taken as reference materials, exhibiting a better self-lubricating performance. Microstructural analysis indicates that the relatively weaker interlayer bonding of the MCMB, smooth interface between the MCMB and matrix, and more cementite formation thorough reaction of MCMB and iron are the key factors behind the enhanced tribological properties. In addition, both the friction coefficients and wear rates of the two groups of composites gradually decrease with the graphite content. This work opens an avenue for designing desirable graphite-based metal friction materials.
石墨-金属复合材料因其自润滑性而被用作摩擦材料，这种自润滑性归因于石墨的层间键较弱。为了克服片状石墨（GrF）填充复合材料摩擦学性能低的缺点，本文开发了以中间相炭微球（MCMB）为固体润滑剂的石墨-铜复合材料。与作为参考材料的GrF-铜复合材料相比，MCMB-铜复合材料具有更低的摩擦系数和磨损率，表现出更好的自润滑性能。微观结构分析表明，MCMB相对较弱的层间键、MCMB与基体之间光滑的界面以及MCMB与铁充分反应形成更多渗碳体是摩擦学性能增强的关键因素。此外，两组复合材料的摩擦系数和磨损率均随石墨含量的增加而逐渐降低。这项工作为设计理想的石墨基金属摩擦材料开辟了一条途径。
