The powders of
ultra fine cemented carbides have high specific surface areas and defect concentrations, so it has high
sintering activity. The ultra fine cemented carbides present different features from common cemented carbides. It is very important to make out suitable sintering technology for ultra fine cemented carbides. The ultra fine WC-10Co-0.8 (VC/ Cr3C2) cemented carbides were made by vacuum sintering in different temperatures. The results of the microstructure and the mechanical properties have been contrasted. It shows that alloy
sintered in 1320℃ has lower hardness and density than that sintered in 1350℃ and 1380℃, but the porosity is higher and WC grain is finer. The alloy sintered in 1350℃ has higher transverse rapture strength than that in 1380℃. The optimum sintering temperature of the ultra fine grain WC-10Co-0.8 (VC/ Cr3C2) cemented carbides is 1350℃. Calorific effects in the course of sintering have been analyzed by
differential thermal analysis. Liquid phase emerges in 950℃ and ends in 1300℃.At the same time, the courses of mass loss and the major gaseous phases evolution are also analyzed. Oxidate impurity in the
grain growth inhibitors VC and Cr3C2 would increase reducing temperature.
More abstracts about the Sintering Features of Ultra Fine Cemented Carbides WC-10Co-0.8 (VC/Cr_3C_2)