Tungsten Carbide Nitride Conversion Method
Compared with ordinary powder, WC nano powder has advantages of small particle size, large surface area and high reactive activity. It has remarkable advantages in chemical synthesis, fuel cell and other fields. Therefore, it is of great significance to study a method for preparing high-quality single phase tungsten carbide nano powders.
Some scholars have provided a method for preparing tungsten carbide nitride nanopowders based on nitride conversion method, including the following steps:
10mmol deionized AMT and 50mmol citric acid were dissolved in 100ml deionized water to get clarified mixed solution; complex reaction was carried out at 70°C for 5 hours; filtration and drying for 12 hours at 120°C, the precursor of tungsten oxide was obtained. The WO3 powder was obtained by calcining at 650°C for 3 hours.
The WO3 powder is placed in a tube furnace and nitrided through ammonia gas. The flow rate of ammonia is controlled at 3L/min, the temperature is 700°C, the heating rate is 2°C/min, and the heat preservation is 2 hours, and the W2N powder is obtained.
10 g of tungsten nitride powder is mixed with 0.62g carbon black, with ethanol as solvent and tungsten carbide ball as ball milling medium, mixed for 24 hours on roll ball mill, rotary evaporation drying, W2N/C mixed powder, W2N/C mixed powder in graphite crucible, and heated to 1100°C under the condition of pressure below 200Pa in carbon tube furnace. The WC nanopowders were obtained at 3°C and the average particle size was 120nm.
Using nitrides conversion method, not only is the raw material cheap and easy to be obtained, but also greatly reduces the synthesis temperature, reduces the cost and energy consumption of raw materials, and the preparation process is simple, practical, controllable and easy to realize scale production.
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