An alternative to liquid-phase sintering for the preparation of highly dense articles from high-speed steel powder is hot forging of porous sintered ingots [4]. Ingots for hot forging are usually sintered in the absence of liquid phase and, therefore, usually have high porosity (15-30%). If the protective atmosphere in annealing furnaces has not been sufficiently dried, the danger that the ingots will be oxidized during heating and transport to the forge is greatly increased.
The activated sintering of high speed steel powder increases the rate of volume densification and improves the perfection of interparticle contacts, which leads to better mechanical properties in the sintered ingots.