The influence of tungsten powder morphology and particle distribution


Tungsten powder and particle distribution will have influence on the compact intensity of products formability (the ability of compaction maintaining its integrity appearance under same pressing conditions).

By using the tungsten oxide that has different content of oxygen such as yellow tungsten, blue tungsten and violet tungsten as raw materials and then obtain 3 kinds of tungsten metal powder that have same average grading but different size distribution and particle morphology through hydrogen reduction as samples, with which the tungsten powder will be suppressed into the samples for strength test by compression molding method. The size of samples should be 12.7mm×6.35mm×31.75mm.

By applying three point bend method, we measure the bending degree of compaction without the forming agent with computer control universal electronic tester. Its span should be 13.5mm, the measuring error equals to 0.01N and its head moving velocity should be 0.5mm/min. Take 5 pieces of compaction samples for each group and measure, and then get their average value.

Measure the powder particle distribution with gravity setting light penetration method and observe the powder morphology with scan mirror

The tungsten powder particle morphology can be effectively regulated and controlled by controlling the proportion of violet tungsten, blue tungsten and yellow tungsten in the raw material of tungsten oxide. Under certain powder Fisher particle size conditions, the forming property of tungsten powder and the tungsten powder compaction strength are influenced a lot by the tungsten powder particle morphology, size distribution and other parameters, in which the forming property will be better and the compaction strength will be higher with higher content of fine particles in the powder and more irregular of the particle morphology.