Meaning
Industrial powder production relies on methods that disintegrate liquid streams into fine particulates. This physical disruption of a melt into discrete droplets is known as atomization. The procedure determines the size, shape, and microstructural uniformity of the resulting powder.
No single nozzle design works for all alloys, and the choice depends on melt viscosity and surface tension.
Energy Input
High-velocity fluids or mechanical rotation supply the force required to overcome surface tension during the breakup. In gas-based systems, pressurized inert gas accelerates through a nozzle to impact the metal stream. This transfer of kinetic energy dictates the average particle size of the batch.
Centrifugal methods instead use a rapidly spinning disc to fling the molten metal outward. The nozzle configuration and gas pressure must be regulated precisely to maintain a stable spray cone.
Droplet Evolution
Solidification of the dispersed metal occurs during its flight through the protective chamber. Rapid cooling prevents the formation of coarse dendritic structures, yielding a highly homogeneous powder. The ambient gas chemistry influences whether the particles remain clean or acquire a thin oxide skin.
Higher cooling rates generally suppress crystalline grain growth.
Powder Quality
Sphericity of the finished powder represents the primary metric for additive manufacturing applications. Highly spherical particles flow more easily and pack with higher density. Fine fractions must be carefully controlled to avoid dust explosion hazards.
Sieve analysis and laser diffraction confirm that the batch meets the required specifications.
