乏油环境下橡胶密封材料在粗糙表面上的摩擦磨损行为研究
Friction and Wear Behaviors of Rubber Sealing Material against Rough Surface under Starved-Oil Condition
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摘要: 在UMT-3多功能摩擦磨损试验机上, 以丁腈橡胶/SiC砂纸配副为研究对象, 系统研究了乏油(包括润滑油和润滑脂)环境下橡胶密封材料在不同粗糙表面上的摩擦学特性, 重点考察了乏油工况下橡胶/粗糙表面摩擦配副的摩擦系数时变性、减摩程度和减摩持久性, 揭示了乏油工况下橡胶在粗糙表面上的损伤机制. 结果表明: 乏润滑剂工况下, 润滑剂的减摩程度和减摩持久性强烈依赖于对偶件表面粗糙程度; 随着对偶件表面粗糙度的降低, 润滑剂的减摩程度呈先缓慢提高后迅速增强的变化趋势, 然而减摩持久性先降低后又逐渐升高. 同时, 乏油工况下的减摩持久性均优于乏脂环境; 在磨损机制上, 随着对偶件表面粗糙度的降低, 乏润滑剂环境下橡胶材料的表面均由伴随明显犁沟特征的严重磨粒磨损逐渐转变为损伤轻微的磨粒磨损. 而在无润滑条件下, 橡胶由典型的磨粒磨损机制损伤特征转变为花纹磨损形貌, 最后又向黏着磨损机制转变.Abstract: Tribological tests for nitrile butadiene rubber (NBR) against SiC abrasive paper with different surface roughness were carried out on an UMT-3 multi-function friction and wear tester. The tribological characteristics of the rubber sealing material against rough surface under starved-oil condition were systematically performed. The time-varying of fiction coefficient, friction-reducing degree and friction-reducing durability were discussed, and the damage mechanism of rubber against rough surface under starved-oil condition was revealed. The results show that friction-reducing extent and durability of lubricant were strongly dependent on surface roughness of the counterpart. With the decrease of the surface roughness, the friction-reducing degree increased slowly and then increased rapidly, while durability of friction-reducing decreased firstly and then increased gradually. Meanwhile, friction-reducing durability of oil lubrication was superior to grease lubrication. For the wear mechanism, with the decrease of the surface roughness, the worn surface of rubber material under starved-oil condition shifted gradually from severe abrasive wear with ploughing characteristic into mild abrasive wear. However, under without lubrication, typical abrasive wear of rubber material was transformed into pattern wear, eventually the wear mechanisms were adhesive wear.