Spheroidization of Fe-Based Powders in Plasma Jet of DC Arc Plasma Torch and Application of These Powders in Selective Laser Melting

摘要

Spheroidization of Fe and steel powders in a plasma stream of an DC arc plasma torch is investigated. The possibility of obtaining a product with a spherical particle content of up to 100% is established. The fluidity of the best samples of obtained powder is 13-20 s with a fluidity of the feedstock of 39 s. The bulk density of the initial powder (3.05 g/cm~3) during the plasma treatment increases to 4.1-4.4 g/cm~3. The nanofraction content in spheroidized powders varied from 0 to 75 wt % and it depends mainly on the enthalpy of the plasma stream, consumption of raw materials, and the organization of the flow of the plasma-forming gas in the discharge channel of the plasma torch. It is established that Fe powders spheroidized in plasma can be used in selective laser melting technology to obtain compact samples whose density reaches 7.86 g/cm~3.