Phase structures of gas atomized equiatomic CrFeNiMn high entropy alloy powder

Abstract In powder technologies such as sintering, 3-D printing, and thermal spraying, the characteristics of the powders are of uttermost importance. This holds for composition as well as for phase and grain structure. In this work, we characterize argon gas atomized Cr25.0Fe25.0Mn24.5Ni25.5 high entropy alloy powder, which is a material of high interest for applications requiring high strength and radiation resistance. The microstructure of gas atomized particles at different class sizes is characterized and the powder properties are determined by nanoindentation and magnetic measurements. The atomized particles have a smooth spherical shape with a fine surface pattern. The composition and phase structure as well as hardness and magnetic properties are particle size dependent, i.e., depend on cooling rate during atomization. The phase structure of the atomized powder is nearly single FCC phase with a small amount of BCC phase, the amount of which increased with the decreasing powder particle size. Average nanohardness determined from nanoindentation of particle class sizes