Preparation process of metallic carbide fine powder

Abstract

The invention relates to a technique for producing the metallic carbide attrition finely pulverized powder; the product is synthesized by metal oxide, carbon black and carbonization accelerant. Mainly, the aldehydes substance is added as the carbonization accelerant during the production process, which can greatly improve the reaction speed and the conversion rate and can produce carbide at a low temperature; also the produced carbide is fine in grain diameter. The carbonization accelerant can expedite the reaction speed because the carbonization accelerant participates in the reaction preferentially, which changes the reaction path, reduces the activation energy of the reaction and the resultant of reaction (carbide) is at a loose porous state, which is favorable for the diffusion process to continue, and so the reaction rate and the conversion rate are improved. Compared with the prior art, the carburizing reaction temperature is reduced 300 DEG C averagely, the reaction time is shortened, the energy consumption during the production is reduced, therefore, the carbonization reaction can proceed completely and sufficiently, the product granularity is fine and the high quality of the product can be guaranteed; meanwhile, the material consumption is minimized and the material is fully utilized.

Description

Technical field: [0001] The invention belongs to the technical field of metal materials, and in particular relates to a preparation process of metal carbide fine powder. Background technique; [0002] As we all know, the preparation and industrialization of ultra-fine-grained cemented carbide is a frontier topic in the development of the world's cemented carbide industry, especially an important topic that industrially developed countries are committed to research and development. Ultrafine or nanocrystalline cemented carbide is made of ultrafine WC and other powders as raw materials, adding appropriate binders, grain growth inhibitors (chromium carbide, vanadium carbide, tungsten-titanium-tantalum-niobium carbide solid solution, etc. Metal carbide), producing cemented carbide materials with high hardness, high wear resistance and high toughness. Its performance is greatly improved compared with conventional hard alloys, and it is more and more widely used in the fields of ...

AI Technical Summary

Problems solved by technology

In this technology, when the carbonized carbon of the metal reacts with the metal oxide, the interface between the carbon and the metal oxide first reacts to form carbon monoxide and corresponding carbides, and the carbides start to nucleate and grow gradually, and then the carbon and oxides pass through Diffusion passes through the carbide and continues to react. Due to the obstruction of the carbide, the diffusion speed will become slower and slower, so the reaction speed will also become slower and slower. Even in the later stage of the reaction, the reaction will not proceed because the reactant cannot diffuse. , so it will lead to low conversion and impure products. To make the reaction go smoothly, carbides must be prepared at a higher temperature. Therefore, increasing the temperature will increase the production energy consumption, and with the increase of the temperature And the time is prolonged, the carbide grains will grow up, after the initial nucleation of the reaction, the carbide grains will gradually grow up, the higher the temperature, the faster the grain growth rate, eventually leading to carbonization in the product Coarse grain

However, there is no catalyst added in the traditional metal carbide production and preparation process, which makes the carbonization reaction insufficient, resulting in waste of raw materials, and has high temperature requirements, and the particle size of the product cannot be guaranteed. It also requires long-term wet ball milling. , to reduce the particle size, not only the cost is high, the efficiency is low, but also impurities such as iron and oxygen are added, which seriously affects the production quality and effect of the product

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