The influence of erodent hardness on the erosion behavior of detonation sprayed WC-12Co coatings

The solid particle erosion behavior of detonation sprayed WC-12Co coatings obtained at three oxygen to fuel ratios has been characterized using SiC, Al2O3 and SiO2 as erodents at two impact velocities (25 m/s, 45 m/s) and two impact angles (30°, 90°). The results indicate that the erosion rate increases with increasing hardness of the erodent and more importantly, the erosion mechanism changes depending upon the erodent type. The ranking of the materials in terms of erosion resistance also depends on the type of erodent used. The extent of decarburization of WC-12Co coatings, varied by using three levels of oxygen to fuel ratio during the coating process has a marginal influence on erosion behavior. The results have been understood in terms of ploughing and sub-surface cracking mechanisms and also on the basis of insufficient transfer of energy from the erodent to the coating especially in the case of SiO2 erodent.