NEW TUNGSTEN CARBIDE POWDER AND ITS MANUFACTURE Russian patent published in 2021 - IPC C01B32/949 C22C29/08 

FIELD: chemistry.

SUBSTANCE: invention can be used in chemical and light industry, metallurgy, military equipment and medicine in the manufacture of hard alloys, cermets, cutting tools such as drills, milling cutters, rotary cutting plates or planing knives, high-load parts such as drill heads, neutron reflectors, armor-piercing projectiles, balls for ballpoint pens, anti-skid spikes for tires or shoes, surgical instruments. First, ammonium paratungstate is calcined, followed by deagglomeration. The resulting WO₃ is mixed with soot, water, and an organic binder. Then the extrusion is carried out into extrudates with a length of less than or equal to 10 mm, which are dried. After that, the tungsten carbide precursor is obtained by heat treatment of the extrudate in a rotating tube or conveyor furnace at 900-1200°C in the presence of minimum amount of argon. The precursor is heat-treated in a pusher furnace at 1300-2000°C in a hydrogen atmosphere. The tungsten carbide obtained by the above-mentioned direct carbidization is deagglomerated and homogenized. Tungsten carbide powder has a specific surface area according to BET of 1.8-2.0 m²/g, the crystallite size c in individual grains is 75-100 nm, the average grain size d is 186-217 nm, the average maximum number n of crystallites per grain is 1.8-2.7.

EFFECT: these characteristics provide easier processing of tungsten carbide powder, increase in the homogeneity and strength of alloys based on it.

5 cl, 7 dwg, 2 tbl