In the context of a waste heat recovery application on a gasoline engine, tribological investigations have been mandatory in the design of a scroll expander. A new design has been proposed to reach higher temperature and investigations are made to ensure that the material of the parts in contact will provide good tribological performances, i.e. a low coefficient of friction and a low wear rate. This research will also prevent high mechanical losses in the machine and, therefore, increase its thermal efficiency. Some experiments have been conducted on six different materials for the tip seal of the expander and two materials for the counter face. Additionally, the experiments have been carried out for a dry and a steam-lubricated contact at several temperatures. This research does not aim to be an exhaustive tribological investigation but instead offers a first comparison between the different materials couples.

中文翻译：

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涡旋膨胀机高温固体润滑材料的研究

在汽油发动机废热回收应用的背景下，在涡旋膨胀机的设计中必须进行摩擦学研究。已经提出了一种新的设计来达到更高的温度，并进行了研究以确保接触部件的材料将提供良好的摩擦学性能，即低摩擦系数和低磨损率。这项研究还将防止机器中的高机械损失，从而提高其热效率。已经对膨胀器端部密封的六种不同材料和配合面的两种材料进行了一些实验。此外，还针对几种温度下的干燥和蒸汽润滑接触进行了实验。