Structural features and properties of alloy 84% WC-16% Co, obtained by hotpressing in the solid and liquid phases I. Effect of the temperature at which the specimens are prepared on their density and structure

Studies are made of changes in the porosity and structure of a hard alloy o btained by hot pressing and sintering within a broad range of temperatures (950-1450 degreesC). The effect of solid- and liquid-phase annealing on the ir porosity and structure is also examined. It is shown that the hot-presse d specimens are denser than the sintered specimens within the solid-phase r egion, other conditions being equal. Solid-phase annealing of her-pressed a nd sintered specimens increases the density of both types of specimens, bur the annealing operation is more effective in the former case. Ir is establ ished that the open pore channels are 2-3 times smaller in the hot-pressed specimens than in the sintered specimens and are no larger than the average size of the tungsten carbide particles. Active growth of the carbide parti cles and redistribution of the ductile phase are observed even in the solid phase. The carbide particles grow considerably faster (by a factor of four ) at sintering temperatures above 1200 degreesC.