Anomalous solidification microstructures in Co-free AlxCrCuFeNi2 high-entropy alloys

A series of cost effective Co-free AlxCrCuFeNi2 high entropy alloys were developed, following the valence electron concentration rule. The solidification microstructure in these alloys showed some anomalies that were rarely seen in other high entropy alloys or multi-component alloys. Specifically, submicron rod-like microstructures existed in the eutectic alloy in spite of the high volume percentage of the rod-like phase; sunflower-like microstructures existed in the hyper-eutectic alloys, with 200 nm sized spinodal decomposed seed particles densely distributed in the disk floret.