含纳微米硼酸盐及二烷基二硫代磷酸锌液体石蜡润滑下钢-钢体系的摩擦磨损性能研究

Friction and Wear Behavior of Steel-Steel Pair Under the Boundary Lubrication of Liquid Paraffin Containing Complex Additive of Nano/Micro Borate and Zinc Dialkyldithiophosphate

在四球试验机上考察了含纳微米硼酸盐及二烷基二硫代磷酸锌 (ZDDP)复配添加剂的液体石蜡润滑下钢 -钢摩擦副的摩擦学性能 .采用 X射线光电子能谱仪和扫描电子显微镜分析了复配体系的作用机理 .结果表明 :纳微米硼酸盐 / ZDDP复配添加剂对钢 -钢摩擦副的抗磨作用产生对抗效应 ,在摩擦过程中的某一阶段摩擦系数突然升高 ,磨损加剧 ;在试验初期 ,磨斑表面较为光滑 ,相应的边界润滑膜为物理和化学吸附膜 ;随着试验时间的延长 ,钢球磨斑表面吸附膜发生破裂 ,磨斑表面变得粗糙并形成微小磨屑碎片 ,相应的摩擦系数突然升高 ;随着试验时间的进一步延长 ,添加剂同钢球磨损表面发生摩擦化学反应 ,并生成含 B、N、S和 P等元素的摩擦化学反应膜 ,从而使摩擦系数波动减小 .

The friction and wear behavior of a steel steel pair under the lubrication of liquid paraffin containing of the complex additive of nano/micrometer borate and zinc dialkyldithiophosphate (ZDDP) was examined using a four ball machine. The worn steel surfaces were analyzed by means of scanning electron microscopy and X ray photoelectron spectroscopy. It was found that the two types of additives showed antagonizing antiwear effect to the steel steel pair. The friction coefficient rose sharply at a certain extended test duration, which was preceded by a relatively smaller and more stable initial value attributed to the physical chemical adsorption boundary lubricating film. Such a kind of sharp increase in the friction coefficient was attributed to the breakage of the adsorbed boundary lubricating film at an extended test duration, at this stage some fine wear debris was observed on the worn steel surface and the wear of the steel steel pair became more severe. With the further extension of the test duration, the trbiological reaction among the additives and the steel rubbing surfaces was initiated, with the generation of the tribochemical reaction film containing B, N, S, and P. This contributed to decrease the fluctuation of the friction coefficient and abate the wear of the steel steel pair significantly as well.