On the construction of erosion–corrosion maps for WC/Co–Cr-based coatings in aqueous conditions

Abstract

In studies of erosion–corrosion of composite-based coatings, there has been an extensive research carried out in recent years. This is because such coatings, which contain hard particles as reinforcements, have the potential to provide an improvement in mechanical properties compared to the un-reinforced base material. In addition, composite-based coatings through the use of a corrosion resistant matrix may offer the ability to improve corrosion resistance compared to the substrate material. In tribology, there is increasing interest in viewing mechanisms of material wastage in a multi-dimensional space. Such a representation or “map” provides a means of identifying the mode of degradation. Incorporation of corrosion variables into the map enables tribo-corrosion regimes to be assigned and wastage rates to be optimized for the operating conditions. In this work, the erosion–corrosion of a composite-based coating was evaluated in sea water conditions. The effects of slurry concentration and potential were studied. Erosion–corrosion maps were constructed based on the results showing the erosion–corrosion mechanism, the level of wastage and extent of synergy between the tribological and corrosion processes.