▎ 摘　　要

NOVELTY - Preparing high-performance ultrafine cemented carbide comprises (i) taking 300-500 g tungsten powder, sodium tungstate or ammonium tungstate and 10-50 g vanadium pentoxide or chromium oxide and mixing uniformly, placing in a methane-filled atmosphere, and supplying a voltage of 15-25 kV for 20-80 minutes; (ii) taking specific amount of ultrafine/nano tungsten carbide, placing into a 1-3 mol/l cobalt nitrate or cobalt sulfate solution, and heat preserving at 120-180℃ for 10-24 hours; (iii) taking specific amount of ultrafine/nano tungsten carbide-cobalt composite powder, 5-15 g cobalt boride, 10-20 g nickel sulfide ball mill for 20-40 minutes; (iv) obtaining 10-15 g graphene oxide and mixing uniformly with the powder; and (v) treating the composite powder at 800-950℃ and 120-135 MPa for 50-150 minutes, cooling in nitrogen atmosphere, and obtaining tungsten carbide-cobalt composite powder cemented carbide with high density and grain size of 300-500 nm. USE - The method is useful for preparing high-performance ultrafine cemented carbide. ADVANTAGE - The method improves the mechanical properties of the cemented carbide, and studies the effects of cobalt content and grain growth inhibitor content on the microstructure and properties of the cemented carbide through comparative examples. DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for high-performance ultrafine cemented carbide prepared by the above method.