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Tungsten Carbides Nano-powders Prepared by Microwave Carbonization Process and Their Performances

Author: LiZuo
Tutor: TangJianCheng
School: Nanchang University
Course: Materials Engineering
Keywords: Microwave carbonization Tungsten carbide nano-powder hydrogenreduction tungsten powder
CLC: TQ136.13
Type: Master's thesis
Year: 2013
Downloads: 35
Quote: 0
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Abstract


Nanocrystalline cemented carbide has broad application prospects because of its high hardness, high wear resistance and high toughness, but the performances of nanocrystalline cemented carbides is directly affected by the microstructure and properties of tungsten carbide nano-powder. Therefore, in this paper, narrow particle size distribution range of tungsten powder was prepared by hydrogen reduction, and the tungsten carbide powder with excellent performance was prepared by microwave carbonization, and to study the mechanism of the preparation of tungsten powder and tungsten carbide powder.Tungsten powder was prepared by purple tungsten and AMT for3hours’ hydrogen reduction in this paper, and the average particle size of tungsten is30nm which is prepared by AMT and the reduction temperature is800℃, and this experiment has discussed the influence of oxygen content of tungsten oxide, hydrogen reduction temperature, reduction time and additives on the performance of tungsten powder.Tungsten carbides nano-powder was prepared by microwave carbonization in this paper, tungsten powder as the tungsten source, and black carbon as the carbon source. black carbon is excellent microwave absorbing material, and black carbon interacts with the electromagnetic field and generated thermal effects during the reaction, the whole tungsten-carbon system is heated by dielectric loss in electromagnetic field caused by black carbon, which make sure the reaction to proceed smoothly. from the comparative experiments, the carbonation temperature of the carbonization reaction, carbonization time, adding a surface active agent, all this factors have an impact on the particle size and performance of tungsten carbide powder, and at the optimal carbonization temperature of1200℃. The average particle size of tungsten carbides is60nm, and microwave carbonization reaction has so many advantages, such as, final product is single, short cycle, low carbonization temperature and low energy loss.

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CLC: > Industrial Technology > Chemical Industry > Inorganic compounds, the chemical industry of the metal elements > Part Ⅵ group metal elements in inorganic compounds > Inorganic compounds of the element chromium vice family ( VI B family) > The inorganic compounds of tungsten
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