Comparison in characteristic and atomization behavior of metallic powders produced by plasma rotating electrode process

Abstract In this study, characteristics of powder for additive manufacturing from three typical alloys Ti-6Al-4V, 316-steel and Co-29Cr-6Mo produced by plasma rotating electrode process (PREP) at 4 rotation speeds are compared in details. The results indicate that for a given rotation speed, alloy with higher ratio of surface tension and density ( γ ρ ) is capable of producing powder with larger particle size and narrower particle size distribution δ (D90-D10). The formation mechanism of the satellite and irregular particle produced by PREP are discussed in detail. The satellite powder is confirmed to be formed by collisions between two particles, and the volume fraction of the satellite powder is lower in the alloy with higher ( γ ρ ) and high thermal conductivity. The formation of irregular powder is possibly related to the peeling of liquid film, which is strongly dependent on the thermal conductivity of alloy.