基体铜的粒度对铜基粉末冶金摩擦材料性能的影响

摘要

采用粒度为270、150、106和75 μm的气雾化纯铜粉作为基体,通过粉末冶金热压烧结的方式,制备铜基摩擦材料.研究基体铜的粒度对材料的物理力学性能、材料组织和摩擦性能的影响.采用MM-3000摩擦磨损试验机测试3000~7000 r/min转速条件下材料的摩擦性能,结果表明:铜粉粒度从270 μm减小到75 μm时,材料的流动性变差,压坯密度降低,材料的硬度呈减小趋势,从18.5 HBW降到14.0 HBW.但是铜粉粒度为106 μm时,硬度反而增加为2.0 HBW.随着转速的升高,摩擦系数呈先增加后减小的趋势,粒度为106 μm的试样摩擦系数比较稳定,摩擦系数变化从0.336到0.348,磨损率也最低,在7000 r/min初速度下仅为47 mg.%Taken gas-atomized copper powder of particle size (270、150、106 and 75 μm) as bases, the copper-based powder metallurgy friction materials were prepared by hotpress sinter. Effect of copper powder particle size on mechanical properties, morphology and friction performance was evaluated by a MM -3 000 friction damage test machine. The rotation speed is 3 000~7 000 r/min,The results showed that the hardness decreases from 18.5 HBW to 14.0 HBW with decrease of copper powder particle size. The material has a biggest hardness of 22.0 HBW when the copper powder particle size is75 μm. The friction coefficient increases and then decreases with the rotation speed increase. The friction coefficient becomes more steady when the copper powder particle size is 75 μm.The friction coefficient increases from 0.336 to 0.348,and rate of wear decreases either. It is only 47 mg when the rotation speed is 7 000 r/min.