A preparation method of cemented carbide nano-particle size powder and high-performance sintered bulk material

Abstract

The invention discloses a preparation method of hard alloy nanoparticle powder and a high-performance sintered block material, and belongs to the technical field of novel materials and novel powder metallurgy. The method comprises the following steps: performing mixing and ball-milling on nano-scale purple tungsten oxide, micrometer-scale cobaltous oxide and vanadium oxide and graphene or a carbon nanotube or a mixture of graphene and the carbon nanotube serving as raw materials; performing cold-pressing on the ball-milled mixed powder to obtain a blank, performing reduction and carbonization reactions in the atmosphere of flowing argon gas to prepare WC-Co-VC powder; and sintering and densifying the WC-Co-VC powder of nano-scale particle diameter by using an ultrahigh solid phase sintering technology to obtain a nano-crystal hard alloy block material with high density and high performance. The hard alloy block material has the advantages of pure material phase, high density, uniform size distribution of nano-crystals, superior mechanical performance, and the like.

Description

technical field [0001] The invention belongs to the technical field of new materials and novel powder metallurgy, and in particular relates to a preparation method of cemented carbide nano-particle size powder and high-performance sintered bulk material. Background technique [0002] In the cemented carbide material system, WC-Co-based cemented carbide has become an indispensable processing tool material in machinery manufacturing, aerospace, petrochemical and other fields due to its high hardness, wear resistance and bending strength. In the 1990s, it was predicted that, compared with traditional coarse-grained cemented carbide, nanocrystalline cemented carbide could have an excellent combination of hardness and toughness, and thus become a more advanced tool material required in high-end technology fields. However, the preparation of WC-Co nanocrystalline cemented carbide materials is still in the stage of laboratory development, and the properties reported at home and abr...

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Problems solved by technology

At present, the powder preparation methods widely used at home and abroad include high-energy ball milling, mechanochemical synthesis, spray conversion, chemical synthesis, sol-gel method, etc. Although nanoscale powders can be prepared, there are complex process routes and uneven particle size distribution. , There are many crystal defects in the powder, especially the prepared powder is prone to rapid grain growth in the subsequent sintering and densification process, and it is difficult to finally obtain a cemented carbide bulk material with nanocrystalline structure

Although many researchers have tried to control the growth of grains during the densification process by using new sintering technologies such as high-frequency induction heating sintering, ultra-high pressure rapid sintering, pulse plasma sintering, and spark plasma sintering, they have successfully prepared nanocrystals with high performance. Carbide reports are still extremely rare

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