The invention discloses a preparation method of ultra-fine
tungsten carbide powder and belongs to the technical field of
powder metallurgy. The preparation method of the ultra-fine
tungsten carbide powder comprises the technological steps that 100
mass parts of
tungsten hexacarbonyl W(CO)6 and 3-5
mass parts of dicobalt octacarbonyl Co2(CO)8 are dissolved in
diethyl ether in a three-opening
bottle and stirred to be completely dissolved, and the
diethyl ether is evaporated through
vacuum distillation, so that a
solid uniform mixture of the ungsten hexacarbonyl W(CO)6 and the dicobalt octacarbonyl Co2(CO)8 is obtained; the three-opening
bottle is heated to the temperature of 50-90 DEG C, carrier gas is introduced to carry the gasified W(CO)6 mixture into a pyrolyzing furnace,
methane gas preheated to the temperature of 300-450 DEG C is introduced into the pyrolyzing furnace at the same time, the temperature of the pyrolyzing furnace is kept being 300-450 DEG C, and the reaction time is 30-120 minutes; and the ultra-fine
tungsten carbide powder which contains 1.0%-6.5% of
cobalt by
mass is finally obtained, and the
granularity D50 of the powder is 50-600 nm. By the adoption of the method, the
granularity of the
tungsten carbide powder can be controlled; in addition, due to the fact that the
tungsten carbide powder is doped with certain
cobalt, abnormal growth of the tungsten
carbide powder during high-temperature
sintering can be restrained, and the excellent performance of the tungsten carbide powder is kept.