Sliding wear characteristics of WC-VC-Co alloys with various Ru additions

Investigations were done on the sliding wear characteristics of the following four alloy series: 80WC-10VC-(10-x)Co-xRu (0 <= x <= 3, 89.6-x)WC-0.4VC-10Co-xRu (0 <= x <= 2, 89.2-x)WC-0.8VC-10Co-xRu (0 <= x <= 2) and 89.6WC-0.4VC-(10-x)Co-xRu (0 <= x <= 3) (wt%), using a CSM ball-on-disk tribometer. All alloys had WC grains less than 1 mu m and mild wear. Increased binder volume fractions increased the wear of 80WC-10VC-(10-x)Co-xRu and 89.6WC-0.4VC-(10-x)Co-xRu (wt%) alloys. The opposite occurred for the (89.6-x)WC-0.4VC-10Co-xRu and (89.2-x)WC-0.8VC-10Co-xRu (wt%) alloys. A direct relationship was found between alloy wear rate and binder mean free path for the 80WC-10VC-(10-x)Co-xRu, 89.6WC-0.4VC-(10-x)Co-xRu and (89.6-x)WC-0.4VC-10Co-xRu (wt%) series. There was an inverse relationship between binder mean free path and wear rate for the (89.2-x)WC-0.8VC-10Co-xRu (wt%) alloys. Alloy wear rate increased with increased mean WC intercept length for all series. There was an inverse relationship between hardness and wear rate for all alloy series. Higher Ru and VC contents increased the wear resistance of the alloys by decreasing the WC grain size. However, VC had a more significant effect on sliding wear than Ru. The 80WC-10VC-(10-x)Co-xRu (wt%) alloys had the lowest wear rates. Higher VC contents could potentially improve the cutting properties. Since there was a limited range of compositions, the effect of Ru on the cutting potential could not be evaluated.