Method for preparing nanometer tungsten carbide powder by acetylene carbonization

Abstract

The present invention provides vapor acetylene carbonizing process of preparing nanometer WC powder. The process adopts WO3 powder of average size 36 nm and specific surface area 12 sq m / g as main material, acetylene as carbon source and H2 as auxiliary gas, with the gas flow rate ratio between acetylene and H2 being 1 to 1.5-4. Acetylene is first preheated at 300-550 deg.c and then led to gas mixer for mixing with H2 to constitute carbonizing atmosphere. The gas mixture is led to 50 mm diameter tubular reaction furnace and reacted with nanometer WC in boat of 10-35 g each at 750-950 deg.c for 1-3.5 hr to produce nanometer level WC powder. The present invention has the advantages of low cost, low reaction temperature, low power consumption and stable WC powder production.

Description

technical field The invention belongs to the technical field of nanometer WC powder preparation, and in particular provides a method for preparing nanometer WC powder by gas-phase carbonization of acetylene. Background technique Tungsten carbide (WC) is a kind of refractory metal carbide and an important component of cemented carbide. Cemented carbide is an important industrial material and is known as "the tooth of industry". Nanocrystalline WC-based cemented carbide is a branch of nanomaterials. After the discovery that nanocrystalline ceramic materials have high fracture toughness and ductility while having high hardness, nanoscale WC / Co powder As raw materials, it produces cemented carbide materials with high hardness, high wear resistance and high toughness. In the past, to prepare WC powder with a particle size of less than 1 μm, it was necessary to prepare fine-grained tungsten powder first, and then undergo a solid-state carbonization reaction with carbon black a...

AI Technical Summary

Problems solved by technology

Over the past 70 years, the production practice of various countries in the world has proved that it is impossible to prepare superfine WC powder with an average WC particle size of less than 0.5 μm by this process.

Moreover, the result of intensified ball milling and crushing will lead to powder fouling, a sharp increase in activity, and the danger of violent oxidation or explosion.

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