Preparation of Titanium Carbide Covered with Tungsten Nanosize Composite Powder from Ammonium Paratungstate 2/2

The specific process is as follows:
1. Preparing W-TiC precursor
(1) Adding TiC powder into oxalic acid solution and dispersion by ultrasonic for 20-30min to make it well distribution. The concentration of oxalic acid is supposed to be 84-134g/L, and the quantity of TiC powder added to be 0.833g/L; in addition, the frequency of ultrasonic is 40KHz and the power is 100-400W;
(2) Adding ammonium paratungstate (APT)into the solution above, the amount of APT added is 56-114.3g/L→heated to 155-185°C, stirring in the constant temperature, reacting for 90-240min→drying→get the W/TiC precursor;



2. Reduction, also the sintering process
Placing the W-TiC precursor prepared by step 1 into the tube oven and sintering in the flowing hydrogen gas, and then powder of titanium carbide covered with tungsten nanosize composite is obtained. The content of hydrogen is at most 99.999%.
The specific sintering process is as follows: [heating rate is 5°C /min, cooling down rate is 5 °C /min].
(1) Heating up to 200°C, keep for 30min;
(2) Then heating up to 500°C, keepfor 60min;
(3) And then heating up to 800°C, keep for 60min;
(4) Go on cooling naturally with the oven after cooling down to 500°C.

The nanosize W-TiC powder prepared by the method has the following prosperities: the composition of tungsten and TiC can be controlled; avoid to introducing impurities, and the purity and degree of uniformity of W-TiC to be very high; the particle size of W-TiC to be 100nm.

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