Preparation of Nanometer Yttrium Oxide Dispersion Tungsten Strengthened Alloy from Ammonium Paratungstate 2/2

Principle: yttrium nitrate and ammonium paratungstate mixed in alcohol, yttrium enter tungsten in ions, and wrapped by tungsten in the process of calcination and reduction, so to achieve the goal of spread in tungsten powder before sintering. After pressing  and sintering, yttrium oxide will remain nanosize and uniformly dispersed in the tungsten crystals.

Reagent: alcohol, yttrium nitrate(Y(NO₃)₃▪6H₂0) ammonium paratungstate, protective gas (vacuum / hydrogen / argon / nitrogen)
Equipment: ball grounding equipment, drying oven, muffle furnace

Concrete implementation steps:
1.  Dissolving yttrium nitrate in alcohol, and mixing with ammonium paratungstate (APT) by ball grounding, the mass ratio of two is 1:1000~1:10, ball grounding speed at 120-180r/min, and time for 0.5-12 hours, and then get wet powder;
2. Put the wet powder into a vacuum drying oven at 40-75°C, drying for 12-36 hours;
3. Placing the dried raw material powder into the muffle furnace for calcination at the temperature of 500-9000°C for 1 to 3 hours, and then powder of nanometer yttrium oxide dispersion tungsten strengthened alloy obtained;
4. The reduction process, put powder of nanometer yttrium oxide dispersion tungsten strengthened alloy in the hydrogen, heated to 600-1000°C for 0.5~2.5 hours;
5. Adding activated sintering agent to the nanometer yttrium oxide dispersion tungsten strengthened alloy powder and sintering and forming into a certain shapes. Sintering at the temperature of 1400-1800°C for 0.5~2.5 hours, and then nanometer yttrium oxide dispersion tungsten strengthened alloy obtained. Remarks: The sintering environment can be compression with heating and isostatic pressing with the protective gas hydrogen, vacuum, argon or nitrogen.

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