A method for preparing superhard cemented carbide rods using wc-co composite powder as raw material by dry bag isostatic pressing and low pressure sintering

Abstract

The invention discloses a method of preparing a superhard alloy bar by using WC-Co composite powder as a raw material through dry bag isostatic pressing and low-pressure sintering. The method is characterized in that the nanometer WC-Co composite powder is used as a raw material, firstly the raw material is put in a dry bag isostatic pressing equipment mold cavity so as to suffer compression molding, and then low-pressure sintering furnace equipment is used for sintering so as to obtain the superhard alloy bar. The method has the beneficial effects that working procedures such as material mixing by wet milling, drying by alcohol volatilization, granulation by blending a forming agent and pressed blank drying in the process of preparing the superhard alloy bar by using low-Co fine-crystalline grain WC as raw materials are omitted, the technological process is short, the equipment operation is simple, and large-sized long bars can be produced.

Description

technical field [0001] The invention relates to a method for preparing superhard cemented carbide rods. The superhard cemented carbide rods prepared by the method are processed into non-standard drill bits or milling cutters, which are used for special tools in the automobile industry. Background technique [0002] The automobile industry is the industry with the most application of special tools, and it is also a symbol to measure the technical level of a country or a tool company. Most of my country's automobile production lines (especially car production lines) are imported from abroad, and cutting tools are mainly imported together with the equipment. At present, domestic automobile production lines include American, European, Japanese and Korean models, as well as independent models mainly based on European equipment. There are five major knife factions active in China: one is Sandvik (including Seco), Sandvik has a large and complex branch of knives, and has the large...

AI Technical Summary

Problems solved by technology

It can be seen that in the traditional process of wet grinding and mixing and drying with volatile alcohol, wet grinding is prone to lattice distortion, material fouling, and uneven mixing, which makes the alloy easy to form uneven growth, cobalt pools, thickening, etc. Defects: The granulation process of mixing molding agents (paraffin, PEG, butadiene rubber, cellulose) is mainly to enhance the viscosity of powder particles and facilitate compression molding. At present, most processes use low-temperature sintering and inert gas to remove molding agents, but molding agents are impossible. Completely excluded, some trace impurities will remain, resulting in residual holes in the prepared cemented carbide, reducing the strength and density of the alloy

At the same time, the residual carbon in the forming agent or the carbon in the stripping agent consumes the carbon in the material, which affects the quality of the prepared cemented carbide, leads to decarburization or carburization of the alloy, and affects the performance of the alloy.

[0006] At present, there is no report on the rapid preparation of superhard cemented carbide using dry bag isostatic pressing + low pressure sintering process using WC-Co composite powder as raw material

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