Wear Resistance of Zirconia-Reinforced WC-6Co Hardmetals: A Case Study

WC-Co composites are widely applied in various industries due to their high hardness and wear resistance. The addition of zirconia further enhanced the composite, improving grain refinement and reducing the friction coefficient. Zirconia submicron particulate reinforcement strengthened the cobalt binder phase, significantly improving the wear resistance. Tribological tests were performed in ball-on-flat dry sliding mode, against an Al₂O₃ counter body. The specimen WC-6Co-10ZrO₂ exhibited a decrease in volumetric loss ΔV by 66% compared to 94WC-6Co composite, and the wear rates W_s showed a 50% decrease for 4 wt.% zirconia addition and up to 80% when 10 wt.% ZrO₂ was added. In tribological tests, a five times larger load, 100 N instead of 20 N, caused an increase in the wear rate 1.1, 1.3, and 1.9 times for WC-Co, WC-6Co-4ZrO₂, and WC-6Co-10ZrO₂ compositions, respectively. Abrasive and adhesive wear mechanisms were identified.