SLURRY EROSION PERFORMANCE OF COLD SPRAYED WC-12Co COMPOSITE COATINGS

In the current investigation, a cold sprayed WC-12Co (WC- Tungsten Carbide, Co- Cobalt) composite coating was deposited on CA6NM steel. Further, microstructural analysis was carried out by using Scanning Electron Microscopy (SEM)/Energy Dispersive Spectroscopy (EDS) and X-Ray Diffraction (XRD) characterization techniques. Mechanical characterization was carried out to measure microhardness, bond strength and surface roughness. The value of coating hardness and surface roughness was measured to be 270 ± 15 Hv and 2.12 ± 0.5 μm. Thereafter, slurry erosion test was performed under accelerated conditions and performance of coated samples was compared under different parameters such as erodent size, impact velocity, angle of impingement and slurry concentration. WC-12Co coatings show no phase transformation or de-carburization of the WC-Co particles as observed in other thermal spray techniques. The WC-12Co coatings was proved to have beneficial erosion reduction rate as compared to untreated CA6NM steel. The slurry erosion performance of coated samples was improved by 68%. SEM images of degraded coatings show the brittle characteristic of WC-12Co coatings.