Phase separation in equiatomic AlCoCrFeNi high entropy alloy

The microstructure of the as cast AlCoCrFeNi high entropy alloy has been investigated by transmission electron microscopy and atom probe tomography. The alloy shows a very pronounced microstructure with clearly distinguishable dendrites and interdendrites. In both regions a separation into anAl Ni rich matrix and Cr Fe rich precipitates can be observed. Moreover,fluctuations of single elements with in the Cr Fe rich phase have been singled out by three dimensional atom probe measurements. The results of investigations are discussed in terms of spinodal decomposition of the alloying elements inside the Cr Fe rich precipitate