Application of U-FAST Technology in Sintering of Submicron WC-Co Carbides.

This article presents the microstructure, hardness, fracture toughness coefficient K IC and phase composition of submicron WC-4Co carbides. The carbides were sintered using the innovative U-FAST (Upgraded Field Assisted Sintering Technology) method, from mixtures of WC-Co powders with an average WC grain size of 0.4 µm and 0.8 µm. The obtained sinters were characterized by a relative density above 99% of the theoretical density. The hardness of the obtained composites was above 2000 HV30, while the K IC coefficient was about 8 MPa m 1/2 .