高石墨铜基复合自润滑材料的组织结构与性能

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

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.

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 ℃ 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.