粉末烧结Cu-C-SnO2多孔材料摩擦磨损特性研究

铜-石墨复合材料是一种优良的导电耐磨材料，但铜与石墨润湿性很差，导致材料的耐磨性能不足。本文通过向原料中加入与石墨亲和性良好的SnO₂，利用粉末冶金的方法制得Cu-C-SnO₂多孔材料，研究了烧结温度及成分配比对烧结体孔隙率、物理特性及摩擦磨损性能的影响。结果表明：烧结体的孔隙率随烧结温度升高而降低，随石墨/SnO₂质量比增大而增大，随非金属/Cu质量比增大而减小；烧结体的密度、硬度、渗油率等与孔隙率密切相关，随孔隙率升高，密度和硬度呈降低趋势，渗油率呈上升趋势；但试样硬度受Cu₂O产生和Cu颗粒再结晶的影响而变化复杂，在烧结温度830℃附近出现突变。干摩擦条件下，试样摩擦磨损特性受材料硬度和石墨相自润滑作用等多重因素影响而变化复杂，随试样硬度和石墨含量的升高而降低；渗油后试样的摩擦磨损特性则主要受油膜润滑控制，与干摩擦相比，相对摩擦因数和磨损率均显著减小，试样磨损率随渗油率的增大而减小，但在石墨/SnO₂质量比0.155附近存在突变。

Study on friction and wear properties of Cu-C-SnO2 porous materials sintered by powders

Copper-graphite composite material is an excellent electrical conductive wear-resisting material.But the wettability of copper and graphite is very poor,resulting in deficient wear resistance of the material.In this paper,Cu-C-SnO₂ porous materials were prepared by powder metallurgy adding SnO₂ which had good affinity to graphite.The effects of sintering temperature and composition proportion on porosity,physical properties,friction and wear properties of the Cu-C-SnO₂ porous materials were investigated.The experimental results show that the porosity of the sintered body decreases with the increase of sintering temperature or non-metal/Cu mass ratio,and increases with the increase of graphite/SnO₂ mass ratio.The density,hardness,and oil penetration rate of sintered body are closely related to the porosity.As the porosity increases,the density and hardness show a decreasing trend,and the oil penetration rate shows an upward trend.However,the hardness of the sample changes complicatedly due to the influence of Cu₂O production and the recrystallization of Cu particles,and a sudden change occurs near the sintering temperature of 830 ℃.Under dry friction conditions,the friction and wear characteristics of the sample are affected by multiple factors such as material hardness and graphite phase self-lubrication,and the wear rate decreases with the increase of sample hardness or graphite content.After oil impregnated treatment,the friction and wear characteristics of the sample are mainly controlled by oil film lubrication.Compared with dry friction,the relative friction factor and wear rate are significantly reduced.The wear rate of the sample decreases with the increase of the oil penetration rate,but there is a sudden saltation near the graphite/SnO₂ mass ratio of 0.155.