Double-layer structure hard alloy with cubic phase-rich surface layer and preparation method thereof

Abstract

The invention belongs to the technical field of alloy materials, and specifically relates to a double-layer structure hard alloy with a cubic phase-rich surface layer and a preparation method thereof.The double-layer structure hard alloy with the cubic phase-rich surface layer comprises the following ingredients and the mass percentage thereof: 4 to 6% of titanium carbide, 6 to 10% of cobalt, 0.1to 1.0% of vanadium carbide, 0.1 to 1.0% of scandium, and 82 to 89.8% of tungsten carbide; and the double-layer structure hard alloy is made by a series of process steps such as ball milling, drying,granulation, compacting and low-pressure high-temperature sintering, etc. According to the double-layer structure hard alloy with the cubic phase-rich surface layer provided by the invention, by adding rare earth metal scandium in the formula, the solubility of nitrogen in a metal binding phase is greatly improved, and the thickness of the cubic phase-rich surface layer of the hard alloy is increased, and the hard alloy has excellent wear resistance; and by controlling the heating rate in the low-temperature sintering process, defect generation is reduced, so that the alloy structure is compact and is more suitable for industrial application.

Description

Technical field [0001] The invention belongs to the technical field of alloy materials, and in particular relates to a double-layer structure cemented carbide with a cubic phase-rich surface layer 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 mechanical processing, mold forming, rock mining, petroleum surveying and construction tools. [0003] Traditional cemented carbide is a composite material formed by uniformly distributed carbide ceramic phase framework and metal bonding phase. Under normal circumstances, when the content ratio of the ceramic hard phase increases, it will help improve the hardness, wear resistance and high temperature resistance, but at the same time it will cause the decrease of toughness; on the contrary, when the content ratio of the metal binder phase inc...

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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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