Tribocorrosion of a CoCrMo alloy in sulfuric acid - Glycerol mixtures

This work reports on the tribocorrosion properties of a CoCrMo alloy sliding under imposed passive potential against alumina in sulfuric acid-glycerol mixtures exhibiting different viscosities and thus, in principle, lubrication properties. As expected, wear accelerated corrosion and friction decreased with increasing glycerol content of the mixture. These results could be successfully rationalized using a recently published tribocorrosion model which considers the interplay of hydrodynamic lubrication with mechanical and chemical deterioration phenomena. The comparison of results with a theoretical model showed that the mixing of glycerol into sulfuric acid aqueous solution promoted lubrication but also that glycerol mechanically weakens the CoCrMo alloy.