Hard alloy with microscopic non-uniform components and structure, and preparation method thereof

Abstract

The invention discloses a hard alloy with microscopic non-uniform components and structure, and a preparation method thereof. The total Co content is 3-30wt% in the hard alloy; the mass percentages of W-containing non-uniform typical contents in a Co phase are 38%, 27.4%, 11%, 7.6%, 5.0% and 1.0% respectively, and the difference between the highest content and the lowest content is 27% (mass percentage); the density of the hard alloy is 14.38g / cm<3>, the bending strength is 2480kg / mm<2>, the HRA hardness is 86.8, and the fracture toughness is 16.3MPa.m<1 / 2>. In the preparation method thereof, the ratio of each component in a premixed alloy powder is compounded through WC-Co alloy aggregates with different carbon contents and common WC powders with different carbon contents, and then the hard alloy with the microscopic non-uniform components and structure is obtained through gel-doping pressing and sintering. The hard alloy with the microscopic non-uniform components and structure, which is prepared by the preparation method disclosed by the invention, has the non-uniform components and structure simultaneously, and therefore is corrosion-resistant, high in toughness and wear-resistant; and new production equipment is not needed in the preparation method thereof, and the preparation method is simple and practicable.

Description

technical field [0001] The invention belongs to the technical field of metal materials, and in particular relates to a cemented carbide with microscopic non-uniform composition and structure and a preparation method thereof. Background technique [0002] For conventional WC—Co-based cemented carbide materials, the WC phase is dispersed in the Co phase, and its metallographic structure is uniform and its mechanical properties are consistent. At the same time, W and C have a certain solubility in the Co phase, and they are not 1:1. The atomic ratio solid solution enters the Co phase, but conforms to [W]*[C]=L, and L is the solubility product, that is to say, if the dissolved carbon content in the Co phase is high, the dissolved tungsten content will be less. The solid solubility of WC in the cobalt phase is affected by the initial carbon content of the alloy. For normal alloys, the W content in the binder phase increases as the carbon content of the alloy decreases, and vice v...

AI Technical Summary

Problems solved by technology

[0018] However, the double alloys proposed by Z.Fang and B.R.Ptterson still have certain limitations in terms of concept and preparation technology: first, the pellets usually prepared by spray powder milling are hollow structures, which are not conducive to the final production of materials. It is dense and unfavorable for industrial practical application; second, using this method, only the double structure can be reached, and the development cannot continue. heavy structure

Third, spray granulation has expensive equipment investment and high production costs. In order to develop this new structure, at the same time, considering industrialization, Chinese scholar Huang Xin and others applied for an invention patent "production of cemented carbide with multiple groups of different components. method" to get the authorization

The temperature range of hot pressing sintering is 1100-1280°C, which is lower than the formation temperature of cemented carbide liquid phase, so as to ensure that no liquid phase is generated during the sintering process, so as to ensure the integrity of the pellet structure. The hot pressing technology requires graphite molds as an auxiliary Sintered tools, which limit the shape and size of the alloy

At the same time, the production cost is very high, and this defect has seriously affected the industrialization process of this technology

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