Tungsten Micro-nano Powder Preparation

Tungsten has excellent physical properties, such as high melting point, high density, high hardness, excellent high temperature strength and high temperature plasticity. Tungsten and its alloys are widely used in equipment manufacturing industry, iron and steel industry, electric power, information industry, petrochemical industry, aviation and aerospace industry, military industry and other fields. The application of new technology and materials of great importance in national defense occupy an important position in our national economy.

A preparation method of tungsten micro-nano powders was proposed. Tungsten micro-nano powders were prepared by pyrolysis of tungsten acid-based inorganic-organic hybrid layered compounds as precursors in a non-oxidizing protective atmosphere. The process includes:

Weigh 10g H₂WO₄, put it into 1000ml conical bottle, add 2ml distilled water to wet, weigh 52g n-octylamine (0.4mol, 66ml) and 360g n-heptane (530ml), mix them evenly, add the mixture of amine and alkane into the conical bottle containing tungstic acid, stir vigorously at the side, and start to be yellow suspension. With the extension of time, the suspension will be uniform. The white suspension was separated from solid and liquid, washed by alcohol 5 times (3000r/min, 10min), and dried at room temperature for 30h. 18G samples of white tungstate-based inorganic-organic hybrid layered compounds were obtained.

Weigh the 0.8830g precursor and put it in the ceramic boat. Place the ceramic boat in the programmable high temperature tubular furnace. The tube is alumina tube. Seal the two ends of the alumina tube, close the exhaust valve and the intake valve, open the vacuum valve, close the vacuum valve, open the intake valve, open the argon gas to the vacuum representation number of 0, open the exhaust valve and the argon gas flow. When the temperature is controlled at 10ml/min, the heating rate starts to rise. The heating rate increases from room temperature to 300 ℃ by adding in at 2 ℃. After 300 C, 10 ℃/min rises to 975 ℃, holding for 5 h, and cooling with the furnace. The sample of 0.3609g is obtained. The X-ray diffraction analysis figure is shown in Fig. 5. It can be seen from the figure that the main phase of the sample is cubic W, and the particle size is about 0.2-2 um.

In this method, tungsten nano-powder was prepared by using tungstic acid-based inorganic-organic hybrid layered compounds as precursors in a non-oxidizing atmosphere. The principle is to reduce tungstic acid in the precursor by using produced by pyrolysis of precursors. Tungstic acid-based inorganic-organic hybrid layered compounds have the characteristics of alternate mixing of inorganic and organic layers, which can ensure that the distribution of tungsten and carbon sources is uniform and fully contacted, which is conducive to the reaction. The method is time-consuming, 2-5 hours can be used, the operation is simple and the requirements for equipment are not high.

• < Prev
• Next >