高石墨铜基复合自润滑材料的组织结构与性能

以Cu-Ni粉末为基体,添加定量的W,SiC,Y2O3和MoS2相,以粉末冶金方法制备石墨质量分数分别为3%,3.5%,4%,4.5%和5%的高石墨含量铜基复合自润滑材料.利用金相显微镜、扫描电镜、X射线衍射仪、共聚焦成像仪和摩擦试验机对样品的组织结构和性能进行分析.结果表明:材料的最佳烧结温度为910℃,烧结时间为4 h;材料的组织由铜的α固溶体,Cu0.8Ni0.19,WMoS2,SiC和石墨等组成.力学性能随着石墨含量的增加而降低,但自润滑效果比较好.在保证材料基体具有高力学性能的基础上,提高材料中固体润滑相的含量,是制备高耐磨自润滑材料的关键因素.

Structure and Properties of Cu-Based Self-Lubricating Composite with High Graphite Content

With Cu and Ni powder used as matrix materials and W, SiC, Y2O3 and MoS2 as additives, the new copper-based self-lubricating composites were prepared by means of powder metallurgy where the graphite content was variable and included 3%, 3.5%, 4%, 4.5% and 5%. The structure and mechanical properties of the samples were investigated by metalloscopy, SEM, XRD, confocal imager, hardometer and tribometry. The results indicated that the best sintering temperature and time of the self-lubricating composites are 910°C and 4 h, respectively. The structure of prepared samples typically consists of the copper's α-solid solution, Cu0.8Ni0.19, WMoS2, SiC and graphite, and their mechanical properties lower with increasing graphite content. However, the self-lubricating performance is improved by increasing graphite. A conclusion is therefore drawn that increasing the content of solid lubrication phase in the composite is the key factor for self-lubricating behavior, though keeping up the high mechanical properties provided by matrix materials is necessary.