Dependence of wear behaviors of hardmetal YG8B on coarse abrasive types and their slurry concentrations

Wear behaviors of hardmetal YG8B were examined in detail through a modified wet sand rubber rimmed wheel test system ASTM B611 using drilling fluids (slurries) with three types of coarse angular sands, SiC, Al2O3 and SiO2, respectively, and an extremely long sliding distance up to more than 60 km was adopted. Under the same condition, the volume loss of hardmetals was positively correlated with the hardness of abrasives, their concentration in slurry and the duration of testing, respectively. But the wear rate was influenced by them in complicated ways. It was positively correlated with the hardness of abrasives and their concentration in slurry. However, it changed in different ways with sliding distance while different abrasive slurries were used. Through morphology observation on the abraded surfaces, the wear mechanism of hardmetals was proposed, which included WC grain fracture, fragmentation and pullout, microcutting, plastic deformation, groove, and binder removal. And when SiC and Al2O3 were used as abrasive, different abraded surface areas on the samples showed different wear mechanisms, but no obvious difference was observed among them with SiO2 as abrasive. The change of abrasive concentration in the slurry had no obvious effect on the wear mechanism.