Effect of Mo and C Additions on Eta Phase Evolution of WC-13Co Cemented Carbides

Abstract

The WC-13Co (wt.%) cemented carbide was prepared by simple pressureless sintering, and the influence of Mo and C additions on the eta evolution and mechanical properties was analyzed by XRD, SEM, EDS, XPS, and Vickers hardness tester. The results show that the addition of Mo has an important influence on the composition, size, and distribution of the eta phase and Mo2C phase. When the Mo content increases from 0 to 2.5%, the Mo-enriched eta phase grows abnormally and the area fraction of the eta phase significantly increases to 40%, leading to an obvious increase in hardness from 1232 HV30 to 1321 HV30, and a decrease in fracture toughness from 12.5 MPa·m1/2 to 9.8 MPa·m1/2. The addition of carbon black effectively inhibits the formation of the eta phase in the samples with 2.5% Mo. Moreover, adding Mo can suppress WC coarsening in a high-carbon content, which is different from the obvious growth of WC grains in a high-carbon environment in traditional research. Finally, the mechanism of eta phase evolution during the sintering process of WC-Co cemented carbides containing Mo is discussed systematically.

Ceramic Films and Coatings: Properties and Applications

“…With the addition of appropriate Fe and C, the hardness of the samples was improved, with an increase in fracture toughness [22]. WC-13Co cemented carbide was produced using the pressureless sintering method; the effects of the Mo and C content on its structure and properties were investigated, and the evolution mechanism of the eta phase during the sintering process was introduced in detail [23]. Finally, there two papers outline anti-corrosion coatings, including conductive and corrosion-resistant phosphate conversion coatings on an AZ91D magnesium alloy [24], and a self-healing microcapsule coating based on epoxy resin [25].…”