Four kinds of Cu-based composites with different mass ratios of graphite and WS2 as lubricants were fabricated by hot-pressing method. Electrical sliding wear behaviors of the composites were investigated using a block-on-ring tribometer rubbing against Cu-5%Ag alloy ring. The results demonstrated that 800 ~C was the optimum sintering temperature for Cu-graphite-WS2 dual-lubricant composites to obtain the best comprehensive properties of mechanical strength and lubrication performance. Contact voltage drops of the Cu-based composites increased with increasing the mass ratio of WS2 to graphite. The Cu-based composite with 20% graphite and 10% WS2 showed the best wear resistance due to the excellent synergetic lubricating effect of graphite and WS2. The reasonable addition of WS2 into the Cu-graphite composite can remarkably improve the wear resistance without much rise of electrical energy loss which provides a novel principle of designing suitable sliding electrical contact materials for industrial applications.
文章以氮化铝(AlN)粉末为基体材料,以氧化钙(CaO)和氧化钇(Y2O3)为烧结助剂,掺杂酸洗处理后的多壁碳纳米管(CNTs)为增韧材料,采用机械球磨后热压烧结的方法制备氮化铝-碳纳米管(AlN-CNTs)复合材料。通过X射线衍射仪(X-ray diffraction,XRD)和扫描电子显微镜(scanning electron microscope,SEM)对AlN-CNTs复合材料的成分结构及微观形貌进行表征,并测试其物理力学性能。研究表明:随着烧结温度的升高,AlN-CNTs复合材料的力学性能也随之提升;在1750℃的烧结温度下,随着碳纳米管质量分数的增加,AlN-CNTs复合材料的抗弯强度和断裂韧性先上升后下降,且当碳纳米管质量分数为1%时复合材料的力学性能最佳。碳纳米管在AlN-CNTs复合材料中的增韧机制主要是碳纳米管的拔出、碳纳米管的桥连和裂纹的偏转。
