Reduction Size Of Tungsten Carbide Powder Oxides

There are many factors that influence reduction size of tungsten carbide powder oxides. Such as tungsten carbide powder properties, impurities, and temperature. Restoration activity of tungsten oxide has obvious effect on the particle size of tungsten powder. Material with bigger restoration activity is more easier to get the tungsten powder with fine grained.

The influence of impurity elements in tungsten particles change, can be divided into three categories. The fist category is that impurity elements which represent by alkali metal can play the carrier effect of oxygen. It can promote chemical reaction and enhanced tungsten powder particles grow. The second one is that calcium, magnesium and silicon have little influence on tungsten particles growing. Besides materials which represent by aluminum can form a thin oxide layer with high stability. Elevated temperature can accelerate the reduction reactions. And it also speed up the creation of water vapor, particle growth and aggregation.

Partial pressure of water vapor is a main factor to powder particle size and shape change. Water vapor is a basic condition to chemical vapor removal reaction, it includes water vapor in hydrogen and reduction reactions. It is not a stable value in the process of recovery.