Enhanced strength and ductility of bulk CoCrFeMnNi high entropy alloy having fully recrystallized ultrafine-grained structure

Publication date: 5 November 2017
Source:Materials & Design, Volume 133
Author(s): S.J. Sun, Y.Z. Tian, H.R. Lin, X.G. Dong, Y.H. Wang, Z.J. Zhang, Z.F. Zhang
A high efficient magnetic levitation melting technique was reported for fabricating bulk equiatomic CoCrFeMnNi high-entropy alloy (HEA) ingot with a diameter of 110mm. The bulk ingot can be either forged or rolled. In particular, fully recrystallized ultrafine-grained (UFG) HEA with a minimum grain size of 503±181nm was successfully obtained through a simple cold rolling and annealing process. The tensile properties of the HEA were studied by changing the grain size from the UFG regime to the coarse-grained regime. The UFG HEA exhibited a good balance of strength and ductility due to the low stacking fault energy. The linear Hall-Petch relationship was well fitted when the grain sizes range from 503nm to 88.9μm.

Graphical abstract

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