A kind of double-layer structure cemented carbide with rich cubic phase on the surface layer and its preparation method

Abstract

The invention belongs to the technical field of alloy materials, and in particular relates to a hard alloy with a double-layer structure whose surface layer is rich in cubic phases and a preparation method thereof. The double-layer structure cemented carbide with rich cubic phase on the surface of the present invention includes the following components and their mass percentages: 4-6% titanium carbide, 6-10% cobalt, 0.1-1.0% vanadium carbide, 0.1-1.0% scandium, and 82% tungsten carbide ‑89.8%, made through a series of process steps such as ball milling, drying, granulation, compacting and low-pressure high-temperature sintering. The double-layer structure hard alloy with rich cubic phase on the surface provided by the present invention greatly improves the solubility of nitrogen in the metal binder phase by adding scandium, a rare earth metal, in the formula, and increases the thickness of the rich cubic phase on the surface of the hard alloy, making it It has excellent wear resistance; by controlling the heating rate during low-temperature sintering, the generation of defects is reduced, making the alloy structure denser and more suitable for industrial applications.

Description

technical field [0001] The invention belongs to the technical field of alloy materials, and in particular relates to a hard alloy with a double-layer structure whose surface layer is rich in cubic phases and a preparation method thereof. Background technique [0002] WC-Co cemented carbide has a series of excellent characteristics such as high hardness, good wear resistance, high red hardness and stable chemical properties. It has been widely used in machining, mold forming, rock drilling, petroleum exploration and construction tools. [0003] Traditional cemented carbide is a composite material formed by interlacing uniformly distributed carbide ceramic phase skeleton and metal binder phase. Usually, when the content ratio of ceramic hard phase increases, it helps to improve the hardness, wear resistance and high temperature resistance, but at the same time it will cause a decrease in toughness; on the contrary, when the content ratio of metal binder phase increases, The o...

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Problems solved by technology

The carbon layer distribution on the surface of this gradient stearic alloy is not uniform, and the carbon layer is thin, which cannot achieve the expected use effect

Chinese patent CN102134660B discloses a functionally graded cemented carbide with rich cubic phase on the surface and its preparation method. The preparation method uses tungsten carbide, compound carbide, titanium carbonitride and cobalt as raw materials, mixes them according to a certain proportion, and uses powder The metallurgical process is molded and formed, and then prepared in a low-pressure furnace by controlling the temperature and nitrogen pressure, but the surface layer of the rich cubic phase on the surface of the cemented carbide is very thin, which cannot reach the value for industrial use

Due to the low solubility of nitrogen in the metal binder phase, the effect of nitriding is not ideal, and the surface layer of the rich cubic phase that can be obtained is very thin and difficult to have industrial application value.

[0006] In summary, there are technical problems such as unsatisfactory nitriding effect and thin surface layer of structurally gradient cemented carbide in the prior art.

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