Behavior of HVOF WC-10Co4Cr Coatings with Different Carbide Size in Fine and Coarse Particle Abrasion

One potential approach to improve the wear performance of HVOF sprayed WC-CoCr -coating in nano- or micro particle wear applications is to reduce carbide size. Better wear performance and smoother worn surface of fine, evenly distributed carbide grains might be due to smaller free path of matrix between carbides. In this study, a modified ASTM G 65 rubber wheel test was used with fine slurry abrasion particles (220 nm) to address effect of coating carbide size, conventional (1 µm),  sub-micron (400 nm), and nano on its wear performance. To understand the wear mechanism the wear tracks were analysed in detailed by using SEM and 3-D profilometer. It was shown that the mechanism of the wear depends on the relative size of the carbide and abrasive particle. By tailoring the carbide size the wear performance can be improved.