二烷基二硫代磷酸钼与功能添加剂复配体系的摩擦学性能

Tribological Properties of the Mixed System of Molybdenum Dialkyl-dithiophosphate Combining with Functional Additive

采用四球磨损试验机考察了摩擦改进剂二烷基二硫代磷酸钼(MoDDP)的摩擦学性能,研究了其与清净剂、分散剂和抗氧剂复配后的协同润滑效果,优选了最佳的复配比例。结果表明,MoDDP具有优异的抗磨减摩性能,质量分数为0.8%的MoDDP具有最优的摩擦学性能。不同添加量的分散剂与MoDDP构成的复配体系呈现协同效应;清净剂、抗氧剂与MoDDP之间存在一最佳复配比例,当MoDDP与清净剂、抗氧剂的配比为2∶1时,复配体系的抗磨、减摩性呈协同增效性。这是由于功能添加剂与MoDDP中的活性元素在摩擦表面存在竞争吸附,从而影响其在金属表面的成膜速率和油膜强度,只有彼此达到最佳的配比时,复配体系的抗磨和减摩性才会呈现协同效应,否则将出现对抗效应。

A four-ball tribotester was performed to study the tribological performance and the synergctic effects of molybdenum dialkyl-dithiophosphate combining with some functional additives, such as detergent, dispersant and oxidation inhibitor. The optimal concentration ratio of friction modifier with functional additives was designed. The results show that MoDDP additive has excellent properties of antiwear and friction reduction, and it has the best tribological property when the content is 0. 8%. There are synergistic effects existing in the anti-wear and friction-reducing capabilities of dispersant with MoDDP. The concentration ratio of MoDDP with detergent and oxidation inhibitor is 2：1 respectively, the mixed system has synergetic effect. Otherwise, there will appear antagonistic effects. The mechanism is inferred that the existing of competitive absorption action of some active elements in MoDDP and functional additives affects the forming film speed and the film intension. Only the optimal concentration ratios are realized, the synergetic lubricating effects appear.