Microstructure and mechanical properties of TiC-WC-(Ti,W)C-Ni cermets

(Ti0.93W0.07)C solid-solution powder is synthesized via high-energy milling and carbothermal reduction. When the solid-solution carbide is sintered after blending with Ni and commercial single-phase carbides such as TiC and WC, a complex microstructure is developed, typically featuring a core-rim structure along with the initial solid-solution phase. Furthermore, an increase in total volume of the solid-solution phase with (Ti0.93W0.07)C in the cermets results in significantly enhanced mechanical properties: fracture toughness (K-1C) is 7.5-12.7 MPa m(1/2) and hardness (H-v) is 11.9-14.1 GPa. These properties are in contrast with those of conventional cermets, which yield K-1C = 6 MPa m(1/2) and H-v = 12.6 GPa. (C) 2009 Elsevier B.V. All rights reserved.