The most important aspect for industrial processes is the transformation of either agglomerated powders produced by spray drying and sintering techniques,or angular powders produced by conventional crushing methods, into spherical powder.
Powder densification and spheroidization is a widely accepted application of induction plasma technology. It essentially consists of in-flight heating and melting of feed material particles followed by cooling and solidification under controlled conditions.
Depending on the size and apparent density of the treated powder, the time of flight of the particle is controlled such that the molten droplets have sufficient time for complete solidification before reaching the bottom of the primary reactor chamber. Finer particles, entrained by the plasma gases, are recovered in a filter downstream of the primary chamber.
Industrial applications benefit already from the unique properties of Tekna’s spheroidization process. The process results in a considerable improvement of the properties of the powder in multiple aspects:
Improved powder flow
Spheroidized particles provide a more homogeneous and stable flow while feeding. This allows feeds to run at faster or slower rates without clogging problems.
Porosity is removed when the material is melted. Increased particle density translates into better material to use in powder metallurgy applications and denser coatings.
Increased powder density
The tap density of the powder is increased by the presence of spherical and dense particles, resulting in denser coating or parts.
Reduced powder friability
Wear on parts and coatings can be reduced by lowering the edging, crumbling, chipping or breakup of the powder used before being processed. The treatment removes internal fractures or weak internal bonds with the end effect of a longer life for the coated parts.