A kind of preparation method of coarse-grained WC-CO cemented carbide

Abstract

The invention discloses a preparation method of coarse-grained WC-Co cemented carbide, comprising the following steps: (1) pretreating WC powder; (2) configuring an activation solution, and then activating the WC powder; (3) filtering and drying Dry the WC powder after the activation, and carry out heat treatment reduction to obtain the WC activation powder body with metal Co particles attached to the surface; (4) configure the plating solution; (5) WC activation powder, C powder and W powder is placed in the plating solution for electroless plating, filtered, cleaned and vacuum-dried to obtain WC / C / W / Co coarse-grained composite powder; (6) WC / C / W / Co coarse-grained composite powder is added to the molding agent and pressed into embryos and sintered into WC‑Co cemented carbide. The method utilizes in-situ reaction sintering to prepare a coarse-grained WC-Co cemented carbide with a grain size larger than 2 μm, which has excellent grain size, hardness, transverse fracture strength and impact toughness.

Description

technical field [0001] The present invention relates to a method for preparing cemented carbide; more specifically, it relates to a method for preparing coarse-grained WC-Co cemented carbide. Background technique [0002] Cemented carbide is a composite material with high hardness, high wear resistance, excellent red hardness, thermal stability and corrosion resistance, high strength and excellent toughness. Among them, coarse-grained WC-Co cemented carbide has excellent hardness, wear resistance and high toughness, and is widely used in fields such as geological and mining tools and tunneling tools. In the preparation of coarse-grained WC-Co cemented carbide, WC powder with an average particle size greater than 20 mm is usually prepared by wet grinding method with moderate ball milling intensity to obtain WC / Co composite powder with consistent particle size and uniform dispersion. The particle size is difficult to control, resulting in the distribution of WC particles in t...

AI Technical Summary

Problems solved by technology

In the preparation of coarse-grained WC-Co cemented carbide, WC powder with an average particle size greater than 20 mm is usually prepared by wet grinding method with moderate ball milling intensity to obtain WC / Co composite powder with consistent particle size and uniform dispersion. The particle size is difficult to control, resulting in the distribution of WC particles in the fired alloy being lower than or exceeding the range of the 2-5 mm coarse grain standard, and finally only WC-Co cemented carbide with a broad peak grain distribution is obtained. When the grain size is the same , the strength and toughness of coarse-grained WC-Co cemented carbide with broad peak distribution are lower than those of narrow peak distribution alloys

In addition, ball milling to obtain high-uniformity composite powder will bring high residual stress to WC particles, which is not conducive to the improvement of alloy properties.

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