A study on development of lubricants for an alternative refrigerant

以R134为制冷剂，以聚亚烷基二醇、多元醇酯、聚乙烯醚为添加剂，研究了Al-Si合金在R134 a中的摩擦磨损性能。研究结果如下：1. R134 a在油中的溶解特性研究结果表明，R134 a在油中的溶解会使油的粘度降低，导致油膜厚度减小或油膜破裂，粘度降低的程度不仅与R134 a在油中的浓度有关，还与油的平均分子量有关. R134 a溶解对油膜形成的影响采用光干涉技术，在球/板往复装置上测量了油膜厚度。随着R134 a在油中溶解度的增加，油膜厚度变薄，Al-Si合金含量增加.在往复滑动接触试验机上考察了R134 a钢/钢和钢/Al-Si合金摩擦副的摩擦磨损性能。钢/钢摩擦副的摩擦磨损特性受摩擦表面形成的吸附膜和/或反应膜以及润滑油表面的固化膜的影响。另一方面，对于钢/Al-Si合金副，Al-Si合金的磨损特性主要由合金向配合钢表面的转移特性控制，该转移特性随着油的极性变高而促进，从而导致磨损增加。

Using R134 as a refrigerant and polyalkylene glycol, and polyolester, polyvinylether, the fiction and wear characteristics of Al-Si alloys, which appear to be promising due to their low density and high strength-to-weight ratio, sliding against steels in R134a with different additives. The results obtained are as follows.1. The solubility characteristics of R134a in oilsIt was confirmed that the dissolution of R134a into oils brought about the reduction of their viscosity leading to the decrease in oil film thickness or to the oil film rupture.The degree of reduction in viscosity was affected not only by the concentration of R134a in oils but also by the mean molecular weight of oils.2. The effect of R134a dissolution on oil film formationOil film thickness was measured by means of an optical interferometry technique with a ball/plate reciprocating apparatus. As the solubility of R134a in oils increased, the oil film thickness became thinner and the amount of Al-Si alloys increased.3. Wear characteristicsThe friction and wear performance was examined with steel/steel and steel/Al-Si alloys pairs in R134a using a reciprocating sliding contact apparatus. With steel/steel pairs, the friction and wear characteristics were significantly affected by absorbed and/or reacted films formed on the rubbing surfaces, and the solidified films on oils. On the other hand, for steel/Al-Si alloys pairs, the wear characteristics of Al-Si alloys was mainly controlled by the transfer property of alloys to the mating steel surface, which was promoted as the polarity of oils became high leading to an increase in the wear.