METHOD OF PRODUCING ULTRAFINE POWDER OF VANADIUM CARBIDE Russian patent published in 2016 - IPC C04B35/56 C01B31/30 B82Y40/00 

FIELD: metallurgy.

SUBSTANCE: invention relates to powder metallurgy, particularly to methods of obtaining ultradisperse powders of vanadium carbide, which are used in production of hard alloys of high speed steel, its substitutes, low-alloy tool and some structural steels and wear-resistant coatings. Method of producing ultrafine powder of vanadium carbide involves preparing a mixture of oxygen-containing compound of vanadium with carbon source, drying and pressing of the obtained powder with subsequent treatment by microwave radiation in argon medium. Initial mixture is produced by neutralisation of aqueous solution of ammonium vanadate to pH 2.5-2.75 by solution of inorganic acid in the presence of the soot taken in ratio V₂O₅:C=1:7 (in terms of oxide). Inorganic acid is HNO₃, HCl or H₂SO₄. Further treatment of the blanks is performed by microwave radiation with frequency of 2,450-3,000 MHz at power of 700-1,200 W and supply of argon at the rate of 5-6 l/h in three stages: at the rate of 15 °C/min up to 300-350 °C; at the rate of 10 °C/min to 700-750 °C and at the rate of 5 °C/min up to 1,100-1,200 °C with holding at final stage within 15-30 minutes.

EFFECT: obtaining ultradisperse powders of vanadium carbide with mean particle size of 235-250 nm using a simple and reliable method.

1 cl, 3 ex, 5 dwg