油溶性纳米Cu作为润滑油添加剂在钢-铜摩擦体系中的摩擦学性能

实验室制备了油溶性纳米Cu润滑油添加剂，将其以1％的质量分数分散于SJ15W／40润滑油中，并以不加该剂的SJ15W／40润滑油作为参比油，采用端面试验机考察其在钢一铜摩擦副体系中的摩擦磨损行为。结果表明，在试验所选定的摩擦时间、载荷、转速条件下，添加了油溶性纳米Cu的润滑体系的摩擦系数和磨损体积都小于参比油，具有优异的减摩抗磨性能。表面分析结果表明，油溶性纳米Cu添加剂能够降低摩擦表面的显微硬度，并显著改善磨损表面的形貌。在摩擦过程中，油溶性纳米Cu添加剂在摩擦面会形成低剪切的膜层，降低摩擦副间的横向剪切力并补偿了磨损，同时在一定程度上修复了磨损表面，表现出低摩擦、低磨损及改善磨损面形貌的性能特征。

TRIBOLOGY BEHAVIORS OF OIL-SOLUBIE NANO-Cu ADDITIVE FOR STEEL-Cu RUBBING PAIRS

Oil-soluble nano-Cu lubricating additive was synthesized in the laboratory. It was revealed that the synthesized material contained nano-Cu with grain size of 3-5 nm observed by using transmit electron microscope. Tribological behaviors of the as-prepared nano-Cu as anti-wear additive of lube oil for CuSn-GCr15 steel rubbing pairs were investigated on an end-face friction and wear tester. SJ 15W/40 lube oil was used as base stock. The results showed that both the friction coefficient and the wear volume were significantly decreased by adding 1% mass fraction of oil-soluble nano-Cu additive compared to the base oil in almost all the tested range of friction time, load and rotation speed. Surface analysis on the worn surface indicated that the microhardness of friction surface could be reduced and the state of worn surface could be obviously improved by adding the oil-soluble nano-Cu additive. A smooth ("soft") tribo-chemical film was formed during the friction process, reducing the cross shearing between the rubbing pairs and decreasing the wear, at the same time, restoring the worn surface, which contributes to the properties of low friction, low wear and improvement of worn surface.