Induction Zone Sintering of WC–8Co Hard Alloy

A new method of the WC–8Co hard alloy sintering is proposed, which consists of sintering a pre- pressed, porous billet moving with a given speed through an induction heating zone of a given temperature. The effect of the sintering temperature in the range of 1200–1380°C on the microstructure, local chemical, and phase composition of the carbide is studied. The induction zone sintering in the presence of a liquid phase does not cause the growth of carbide grains. The grain size of tungsten carbide sintered in the temperature range of 1240–1280°C and travel speed of 3 mm/min decreases from 3.9 μm to 1.9 μm, and an increase in the billet displacement rate from 3 to 6 mm/min promotes the formation of the η-phase, presumably due to a large temperature gradient. The refinement of the structure causes a monotonic increase in the HV1 hardness from 417 to 664.