WC-10 wt.%Co hard alloy fabrication via spark plasma sintering of mechanically activated powders

Abstract

Subject of research: the paper presents a method of hard alloy fabrication via spark plasma sintering technology performed for mechanically activated powders of mixed WC compositions with 10 wt % Co. Methods and objects of research: mechanical activation of the powders was carried out in a ball planetary mill by wet milling/stirring in anhydrous isopropanol medium using a milling container and balls made of WC. Main results of research: the paper presents experimental data on the densification dynamics (kinetics and sintering stages) during spark plasma sintering at temperatures of 1000, 1100, 1150 and 1200 С. The results of studies of the phase composition, microstructural organization and physical and mechanical properties of WC-10wt.%Co hard alloy are given. Optimal sintering parameters (1200 C, 9 min) are determined. Hardness and mechanical strength of WC-10wt.%Co hard alloy samples increase as the sintering temperature increases with reaching the density of 99.6 % of the theoretical value. It is shown that with increasing temperature from 1000 to 1200 C the average WC grain size slightly increases from 3.3 m to 3.9 m with increasing contribution of the share of larger grains with size 4 m.