Microstructure and mechanical properties of Al0.7CoCrFeNi high-entropy-alloy prepared by directional solidification

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Gang Liu
  • Lin Liu
  • Xinwang Liu
  • Zhenhua Han
  • Guojun Zhang
  • A. Kostka

Detail(s)

Original languageEnglish
Pages (from-to)93-100
Journal / PublicationIntermetallics
Volume93
Online published1 Dec 2017
Publication statusPublished - Feb 2018
Externally publishedYes

Abstract

The high-entropy-alloy Al0.7CoCrFeNi (molar ratio) was prepared by vacuum arc melting followed by directional solidification (DS) with <001> oriented seed. The unique lamellar-dendrite microstructure was obtained over a wide cooling rate range. During solidification, Fe and Co are prone to segregate to the dendrite, while Cr and Al segregate to interdendrite. The solute pile-up of Cr and Al at the solid/liquid interface leads to the dendritic solidification. During the following cooling process, the BCC phase precipitates from the FCC dendrite to form the lamellar structure, while the ordered B2 phase precipitates from the interdendrite. Moreover, the lamellar spacing is significantly refined with increasing cooling rate, resulting in the higher hardness and compressive yield strength. Directional solidification is proved to be an efficient way to improve the mechanical properties of multi-phases high-entropy alloys.

Research Area(s)

  • Alloy design, Crystal growth, High entropy alloy, Microstructure, Transmission electron microscopy (TEM)

Citation Format(s)

Microstructure and mechanical properties of Al0.7CoCrFeNi high-entropy-alloy prepared by directional solidification. / Liu, Gang; Liu, Lin; Liu, Xinwang; Wang, Zhijun; Han, Zhenhua; Zhang, Guojun; Kostka, A.

In: Intermetallics, Vol. 93, 02.2018, p. 93-100.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review