镍与石墨含量对新型铜基粉末冶金受电弓滑板材料性能的影响

Effects of nickel and graphite content on new copper matrix P/M materials for pantograph slider

采用粉末冶金法,在N2和H2混合气氛保护下烧结,制备以石墨和镍等为主要合金元素的新型铜基受电弓滑板材料,研究石墨含量对该材料电阻率、冲击韧性、硬度、摩擦因数和磨损性能的影响,以及镍含量对其硬度和冲击韧性的影响,并分析烧结过程中形成的弥散相和固溶体对材料的增强增韧效果。结果表明:石墨对材料密度影响较明显,石墨含量越高,材料的电阻率越大,冲击韧性越小,并且摩擦因数越小,减磨和耐磨性越好,但石墨含量超过5%时材料性能下降;随镍含量增加,受电弓滑板材料的硬度和冲击韧性都提高,但电阻率增大。石墨和镍的含量(质量分数)均为3%时,材料的电阻率为0.22μΩ·m,硬度为HB60,冲击韧性为7.1J/cm2,摩擦因数为0.19,能满足铜基受电弓滑板的使用要求。

A new type of copper-based pantograph slider materials mainly composited of graphite and nickel, was successfully prepared by sintering specimen in an atmosphere of N2 and H2 gas mixture. The effect of graphite content on electrical resistivity, impact toughness, hardness, friction coefficient and wear performance and the effect of nickel content on impact toughness, hardness were studied. The toughening and strengthening effects of solid solution and dispersed phase were also analyzed. The results show that the higher graphite content can cause the greater resistivity, the smaller impact toughness and friction coefficient, and the better anti-friction and wear performance. But the performance of material decreases when the graphite content is more than 5%. Moreover, the higher the nickel content can induce the greater hardness, the bigger impact toughness and the greater resistivity. When the content of graphite and nickel both are 3%, the performance with electrical resistivity of 0.22 μΩ.m, hardness of HB60, impact toughness of 7.1 J/cm2, and friction coefficient of 0.19 can be obtained, which can meet the basic requirements of national standards.