Heterogenous columnar-grained high-entropy alloys produce exceptional resistance to intermediate-temperature intergranular embrittlement

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

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Author(s)

Detail(s)

Original languageEnglish
Article number113622
Journal / PublicationScripta Materialia
Volume194
Online published18 Nov 2020
Publication statusPublished - 15 Mar 2021

Abstract

High-entropy alloys (HEAs) strengthened by coherent nanoparticles show great potentials for elevated-temperature structural applications, which however, generally suffer from a severe intergranular embrittlement when tested at intermediate temperatures. In this study, we demonstrated a novel “heterogenous columnar-grained” (HCG) approach that can effectively overcome this thorny problem. Different from the equiaxed counterpart which shows extreme brittleness along grain boundaries at 800 °C, the newly developed HCG-HEA exhibits an exceptionally high resistance to intergranular fractures originating from the unique grain-boundary characters and distributions. The presence of heterogenous columnar grain structure drastically suppresses the crack nucleation and propagation along with boundaries, resulting in an unusually large tensile ductility of ~18.4 % combined with a high yield strength of ~652 MPa at 800 °C. This finding provides a new insight into the innovative design of high-temperature materials with extraordinary mechanical properties.

Research Area(s)

  • grain boundary embrittlement, grain boundary structure, high-entropy alloy, precipitation strengthening

Citation Format(s)

Heterogenous columnar-grained high-entropy alloys produce exceptional resistance to intermediate-temperature intergranular embrittlement. / Cao, B.X.; Kong, H.J.; Fan, L.; Luan, J.H.; Jiao, Z.B.; Kai, J.J.; Yang, T.; Liu, C.T.

In: Scripta Materialia, Vol. 194, 113622, 15.03.2021.

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