Twinning engineering of high-entropy alloys: An exercise in process optimization and modeling

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:822

Article

Moon, Jongun^1,2  Bouaziz, Olivier^3,4  Kim, Hyoung Seop^1,2,5  Estrin, Yuri^6,7 

[1] Pohang Univ Sci & Technol POSTECH, Dept Mat Sci & Engn, Pohang 37673, South Korea

[2] Pohang Univ Sci & Technol POSTECH, Ctr High Entropy Alloys, Pohang 37673, South Korea

[3] Univ Lorraine, Lab Etud Microstruct & Mecan Mat LEM3, Arts & Metier Paris Tech, CNRS, F-57000 Metz, France

[4] Univ Lorraine, LAB EXcellence DAMAS, F-57000 Metz, France

[5] Pohang Univ Sci & Technol POSTECH, Grad Inst Ferrous Technol, Pohang 37673, South Korea

[6] Monash Univ, Dept Mat Sci & Engn, Clayton, Vic 3800, Australia

[7] Univ Western Australia, Dept Mech Engn, Crawley, WA 6009, Australia

关键词: High-entropy alloys;    Twinning;    Recovery;    Strain hardening;    Modeling;   

DOI  :  10.1016/j.msea.2021.141681

来源: Elsevier

【 摘 要 】

In a bid to improve the mechanical properties of high-entropy alloys, particularly, their strain hardening capability, we adapted the time-proven concept of 'twinning engineering', developed in the context of TWIP steels, to twinning-assisted high-entropy materials. The strategy chosen involved a two-step thermomechanical processing that consisted of low-temperature pre-straining and subsequent annealing. This approach was trialled on CoCrFeMnNi as an exemplary high-entropy alloy. The annealing conditions selected ensured that the deformation twins generated under low-temperature deformation were retained, whilst the dislocation density was recovered. The viability of this strategy was convincingly confirmed for room temperature deformation of the alloy. A constitutive model accounting for the effect of the pre-straining induced deformation twins was proposed. It was shown to provide a reliable description of the low-temperature and room-temperature deformation behavior of CoCrFeMnNi when deformation twins are involved.

【 授权许可】

Free