A study on development of lubricants for an alternative refrigerant

使用R134作为制冷剂和聚亚烯乙二醇、聚脂、聚乙烯醚，研究了Al-Si合金（由于其低密度和高强度重量比而显得很有前途）在含有不同添加剂的R134a钢中滑动的性能和磨损特性。得到的结果如下：1。R134a在油品中的溶解特性证实了R134a在油品中的溶解使油品粘度降低，导致油膜厚度减小或油膜破裂。粘度的降低程度不仅受油中R134a浓度的影响，还受油的平均分子量的影响。R134a溶解对油膜形成的影响采用球/板往复仪光学干涉测量技术测量了油膜厚度。随着R134a在油中的溶解度增加，油膜厚度变薄，Al-Si合金用量增加。磨损特性采用往复滑动接触装置研究了R134a中钢/钢和钢/Al-Si合金副的摩擦磨损性能。对于钢/钢副，摩擦表面形成的吸收膜和/或反应膜以及油表面的固化膜对摩擦磨损特性有显著影响。另一方面，对于钢/Al-Si合金对，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，随着油极性的提高，合金向配合钢表面的转移特性得到促进，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.