Plasma spheroidization process is used to tranform irregular shaped particles into spheres in order to increase flowability and packing density of the powder. These are essential properties for powder to be usable in additive manufacturing processes such as laser powder bed fusion to reach homogenous and repeatable spreading of the powder on to the powder bed.
The particles are melted within a plasma and the liquid metal forms spherical droplets that rapidly cool down after leaving the plasma during a freefall in the process chamber, as shown in the figure below.
Plasma spheroidization process (after Jun-Seok Nam, Eonbyeong Park, Jun-Ho Seo
Metals and Materials International 26, 491–500 2020)