In situ neutron diffraction study of fatigue behavior of CrFeCoNiMo0.2 high entropy alloy

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

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Author(s)

  • Dong Ma
  • Alexandru D. Stoica
  • Zhenduo Wu
  • Si Lan

Detail(s)

Original languageEnglish
Article number107371
Journal / PublicationIntermetallics
Volume139
Online published29 Sep 2021
Publication statusPublished - Dec 2021

Abstract

In situ neutron diffraction measurement was applied to study the low-cycle fatigue behavior of CrFeCoNiMo0.2 high entropy alloy. A two-step stress-controlled fatigue test with a stress range of 100–460 and 20–500 MPa was employed. The as-cast sample was cycled 129,000 and 61,000 times, respectively, before fracture. The evolution of the lattice strain and peak intensity demonstrates that the main deformation mechanism is dislocation slip, while no evidence of stacking fault was found. A three-stage ratcheting was clearly observed. Under the stress-controlled mode, the experimentally determined dislocation density increases linearly with the ratcheting strain. The increase of the dislocation density results in a decay of the ratcheting strain rate, which stabilizes the structure and is beneficial for fatigue resistance.

Research Area(s)

  • High-entropy alloy, Low-cycle fatigue, Neutron diffraction measurement, Ratcheting