Ultrafine Tungsten Powder Preparation by Doping Rare Earth Yttrium

In order to improve the properties of tungsten and tungsten alloys, yttrium doping is a very effective method. It can improve the properties of tungsten and tungsten alloys by changing the reaction sequence, affecting the skeleton and growth, and forming second phase reinforcement phase. Therefore, researchers have developed a method for preparing ultrafine tungsten (W) powder by doping rare earth yttrium (Y) with ammonium paratungstate (APT).

The technological steps for preparing ultrafine tungsten powder by doping rare earth yttrium are as follows:

(1)Yttrium was added into ammonium paratungstate in the form of Yttrium nitrate (Y(NO₃)3·6H₂O) to prepare precursor complex solution. The content of Yttrium was 0.001%~5%(quality).

(2)The precursor composite powder was obtained by grinding the precursor composite solution after drying for 8-10 h at 70-90 ℃.

(3)Yellow tungsten oxide powders were prepared by calcining the precursor composite powders at 580 620 and holding time of 2-3 h.

(4)Superfine tungsten powder was prepared by reducing yellow tungsten oxide powder in hydrogen atmosphere at a heating rate of 5 /min, heating to 780 ~820, holding for 3h~4h.

Ultrafine tungsten powder was prepared by adding Yttrium nitrate (Y(NO₃)3·6H₂O) into APT. A new monoclinic Y₂WO₆ phase was formed by doping rare earth Y. The obtained tungsten powder was uniform and fine with obvious refining effect. Its laboratory operation is as follows:

The ultrafine tungsten powder prepared by the method described above is uniform and fine with a particle size of 350-450 nm. The refinement effect of doping rare earth Y is obvious. The process is simple, green and environmental friendly, and the production cost is low. It is suitable for batch production in factories.

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