This study is conducted to examine the tribological performance of WC-12Co coating and WC-12Co mixed with yttrium oxide coating applied on mild steel. Mild steel machinery is usually used for hydropower generation but the sediments present along with the river water cause wear on the machinery surface. DUCOM slurry pot tester setup was used for the experiments. This study was based on the coatings of WC-12Co as well as the mixing of yttrium oxide with WC-12Co powder in various proportions ranging from 1–3% by weight on mild steel. The high-velocity oxygen fuel thermal spray coating process was used to deposit a microlayer coating on the mild steel. It is observed that the microhardness of the coatings increases with the addition of yttrium oxide. The experiments were carried out varying the concentration, rotational speed, and test duration in the range of 10–40% by weight, 750–1500[Formula: see text]rev/min, and 30–120[Formula: see text]min duration, respectively. It is observed that the WC-12Co+2%Y2O3 coating has a higher erosion resistance.