Tungsten powder is the main aterial of hard alloy,also do the tungsten-based alloy.However,tungsten powder belongs to brittle material,there is a contradiction between the hardness and intensity:higher hardness cause lower intensity,higher intensity cause lower hardness.In order to improve the capability ,refine tungsten powder bacomes a trend for making superior product.By pressing submicron tungsten powder,tungsten we get tungsten with more hardness and tenacity.

 

The process of redox cycle to produce submicron spherical tungsten powder from ammonium paratungstate as belows:

1.Raising the temperture of purity ammonium paratungstate and argon up to 800℃,keep in 800℃ for 10 minutes,we get purple 

tungsten,

2.Deoxygenize purple tungsten we obtained in step1,comes tungsten powder,

3.Raising the tempreture of tungsten powder we obtained in step2 up to 500℃ in the air for first time oxidation,keep in 500℃ for 10 minutes,tungsten trioxide comes,
4.Dexoygenizing tungsten trioxide we obtained in step3 in the hydrogen for the second time,tungsten powder comes,

5.Repeat step3 for the second time oxidation,we get tungsten trioxide,

6.Use the tungsten trioxide obtained in step5 for third time dexoygenizition repeat step2,then we get submicron spherical tungsten powder.