Dynamic abrasion resistance of coatings applied to engineering materials

Abstract Combined impact and abrasion tests were conducted on coated and uncoated samples of aluminium, mild steel, and tool steels using a purpose built test rig. Tungsten carbide-cobalt (WC-Co) coatings of different thicknesses were deposited using a high velocity oxyfuel (HVOF) process. Experimental work showed that wear rates were greater under impact abrasion conditions compared with pure contact abrasion. As the substrate hardness increased, the wear rates decreased under the test conditions. Coated aluminium samples experienced greater wear under impact conditions than uncoated samples. This was due to deformation of the substrate which led to cracking and spalling of the coatings. Impact abrasion produced greater wear on the mind steel than pure abrasion. The tool steels experienced very low wear rates under both test conditions and only slight polishing of the surfaces occurred. Results show that the wear rate on each sample was not affected by the coating thickness, but the coating thickness did influence the wear resistance.