High impact toughness of CrCoNi medium-entropy alloy at liquid-helium temperature

We show that face-centered-cubic CrCoNi medium-entropy alloy sustains a Charpy V-notch impact toughness (AK) as high as 340 J at 4 K. Deformation twinning (DT) is rendered exceptionally profuse by this alloy's low stacking fault energy, combined with liquid-helium temperature and high strain ra...

Full description

Saved in:
Bibliographic Details
Published inScripta materialia Vol. 172; pp. 66 - 71
Main Authors Yang, Muxin, Zhou, Lingling, Wang, Chang, Jiang, Ping, Yuan, Fuping, Ma, Evan, Wu, Xiaolei
Format Journal Article
LanguageEnglish
Published Elsevier Ltd 01.11.2019
Subjects
Ductility
High-entropy alloy
Impact fracture toughness
Strain hardening
Twinning
Impact fracture toughness
Twinning
Ductility
Strain hardening
High-entropy alloy
Online AccessGet full text

Cover

More Information
Summary:We show that face-centered-cubic CrCoNi medium-entropy alloy sustains a Charpy V-notch impact toughness (AK) as high as 340 J at 4 K. Deformation twinning (DT) is rendered exceptionally profuse by this alloy's low stacking fault energy, combined with liquid-helium temperature and high strain rates that both incur high stresses to favor DT across a large plastic zone. This efficiently dissipates imposed mechanical energy, accumulates defects to sustain high strain hardening, and restrains strain localization events from evolving into major shear bands. Martensitic transformation to hexagonal phase is insignificant. CrCoNi is therefore a strong competitor to the best existing cryogenic alloys. [Display omitted]
ISSN:1359-6462
1872-8456
DOI:10.1016/j.scriptamat.2019.07.010