Tribological Improvement of Carbon/Carbon Composites by Infiltration of ZnO/Al_2O_3/ZrO_2 Solid Lubricant Coatings

摘要

Carbon/Carbon composite (CCC), a well-recognized structural material, is known for its high temperature strength and low relative density. Since most of its applications involve an oxidizing environment, the improvement in high temperature oxidation behavior needs to be addressed. Furthermore, fretting wear of uncoated CCC limits its lifetime in applications, such as bushings in jet engines. A number of investigators have reported enhancement in oxidation and wear resistant of CCC in the presence of protective coating layers. But application of a surface and subsurface coating system that can preserve its oxidation resistance along with maintaining lubricity at high temperature remains an issue. Therefore, the main motivation of this research was to infiltrate the porous CCC with atomic layer deposited (ALD) lubricious oxides, which have been shown to provide good tribological properties, and determine the solid lubrication mechanisms responsible for the improvements in wear resistance with electron microscopy.