(WC+SiC_(w))/Cu-Al_(2)O_(3)复合材料载流摩擦磨损行为

Current Carrying Friction and Wear Behavior of(WC+SiC_(w))/Cu-Al_(2)O_(3) Composites

目的研究相同载流条件下纳米Al_(2)O_(3)颗粒、微米WC颗粒和SiC晶须对(WC+SiC_(w))/Cu-Al_(2)O_(3)复合材料表面摩擦磨损性能的影响。方法采用粉末冶金法和内氧化法相结合的方式,制备了(WC+SiC_(w))/Cu-Al_(2)O_(3)复合材料,并利用HST-100高速载流摩擦试验机进行载流摩擦磨损性能测试。采用透射电镜和扫描电镜观察复合材料的显微组织和载流摩擦磨损表面形貌。研究不同的增强相对(WC+SiC_(w))/Cu-Al_(2)O_(3)复合材料磨损性能的影响,分析其磨损机理。采用AUTOGRAPH AG-I 250 kN拉伸设备对试样进行拉伸,并分析抗拉强度与磨损性能的变化关系。结果(1WC+2SiC_(w))/Cu-Al_(2)O_(3)复合材料的硬度和极限抗拉强度相较于Cu-Al_(2)O_(3)复合材料分别提高了20.2%和12.7%。(1WC+2SiC_(w))/Cu-Al_(2)O_(3)复合材料的摩擦系数最小,为0.33,相对Cu-Al_(2)O_(3)复合材料降低了42.1%。(1WC+2SiC_(w))/Cu-Al_(2)O_(3)复合材料表面磨损形貌最为光滑,无大面积电弧烧蚀现象,犁沟数量少且浅。结论(WC+SiC_(w))/Cu-Al_(2)O_(3)复合材料的磨损机理主要是粘着磨损、磨粒磨损和电弧烧蚀;纳米级Al_(2)O_(3)颗粒、微米级WC颗粒和SiC晶须三者协同强化铜基体,提高了复合材料的强度和硬度,从而降低了铜基复合材料的摩擦系数和磨损率。WC颗粒和SiC晶须采用合适质量配比时,可以有效地改善Cu-Al_(2)O_(3)复合材料的磨损情况。

The aim of this paper is to study the effect of nano-Al_(2)O_(3) particles,micro-WC particles and SiC whiskers on the surface friction and wear properties of(WC+SiC_(w))/Cu-Al_(2)O_(3) composite under the same current carrying conditions.The(WC+SiC_(w))/Cu-Al_(2)O_(3) composites were prepared by powder metallurgy and internal oxidation,and their current carrying friction and wear properties were tested by HST-100 current carrying high speed tester.The microstructure of the composite materials and its surface morphology after current carrying friction and wear test were observed by transmission electron microscope and scanning electron microscope.The effects of different reinforcing phases on the wear property of(WC+SiC_(w))/Cu-Al_(2)O_(3) composites were studied and the wear mechanism was analyzed.The samples were drawn using an AUTOGRAPH AG-I 250 kN drawing device and the relation between tensile strength and wear property was analyzed.The results show that the hardness and ultimate tensile strength of(1WC+2SiC_(w))/Cu-Al_(2)O_(3) composites are 20.2%and 12.7%higher than those of Cu-Al_(2)O_(3) composites.The friction coefficient of(1WC+2SiC_(w))/Cu-Al_(2)O_(3) composite is the least(0.33),which is 42.1%lower than that of Cu-Al_(2)O_(3) composite.The wear morphology of(1WC+2SiC_(w))/Cu-Al_(2)O_(3) composite is the smoothest,and there is no large area arc ablation,and the number of grooves is small and superficial.Therefore,the wear mechanism of(WC+SiC_(w))/Cu-Al_(2)O_(3) composite is mainly relevant to adhesive wear,abrasive wear and arc ablation;Nano-Al_(2)O_(3) particles,micro-WC particles and SiC whiskers strengthen the copper matrix and improve the strength and hardness of the composite,thus reducing the friction coefficient and wear rate of the copper matrix composite.Besides,the wear of Cu-Al_(2)O_(3) composites can be effectively improved when the mass ratio of WC particles and SiC whiskers is appropriate.