Frictional Properties of CeO₂-Al₂O₃-ZrO₂ Plasma-Splayed Film under Mixed and Boundary Lubricating Conditions

Abstract

In order to find a counterpart for reducing the frictional coefficient of Al₂O₃-ZrO₂-CeO₂ plasma-splayed film, the sliding properties in mixed and boundary lubricating conditions was investigated. It was found that combination of a CrN-coated cast iron pin and an Al₂O₃-ZrO₂-CeO₂ plasma sprayed plate provided the lowest frictional coefficient among several combinations chosen from practical materials. The coefficient of friction was much lower than that of the materials combination widely used for piston ring and cylinder liner. It was inferred that the combination of a pin made of hard materials with high density, a smooth surface such as CrN-coated cast iron and a porous plate can reduce the frictional coefficient because less sliding resistance is implemented and porosity retains oil.