Characterization of AlCoCrFeNi High Entropy Alloy Gas Atomized Powder

Abstract

AlCoCrFeNi alloys are widely studied due to the combination of high strength in a wide temperature range, good corrosion and wear resistance, but they typically present low ductility. Due to this limited ductility, traditional bulk fabrication processes that involve forming are difficult, and casting processes are also non-ideal due to pronounced segregation and coarse microstructure. Therefore, both the selective laser melting and the powder metallurgy are more promising routes for this alloy, both of these use powder as starting material. This work aimed to produce powder of Al₂₀Co₂₀Cr₂₀Fe₂₀Ni₂₀ alloy by gas atomization and to perform its detailed characterization.The results show that the powder is mainly spherical, which resulted in good flowability. Most of the powder (62%) has a size smaller than 75µm, and microscopy analyses confirmed that a B2 dendritic microstructure was formed, with A2 cuboidal precipitates.

Keywords:
High entropy alloys; gas atomization; powder metallurgy