Comparison of cryogenic deformation of the concentrated solid solutions CoCrFeMnNi, CoCrNi and CoNi

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

卷:783

Article

Tirunilai, A. S.¹  Hanemann, T.²  Reinhart, C.³  Tschan, V²  Weiss, K-P²  Laplanche, G.³  Freudenberger, J.^4,5  Heilmaier, M.¹  Kauffmann, A.¹ 

[1] Karlsruhe Inst Technol, Inst Appl Mat IAM WK, Engelbert Arnold Str 4, D-76131 Karlsruhe, Germany

[2] Karlsruhe Inst Technol, Inst Tech Phys ITEP, Hermann von Helmholtz Pl 1, D-76344 Eggenstein Leopoldshafen, Germany

[3] Ruhr Univ Bochum Rub, Inst Mat, Univ Str 150, D-44780 Bochum, Germany

[4] Leibniz Inst Solid State & Mat Res Dresden IFW Dr, Helmholtzstr 20, D-01069 Dresden, Germany

[5] Tech Univ Bergakad Freiberg, Inst Mat Sci, Gustav Zeuner Str 5, D-09599 Freiberg, Germany

关键词: Alloy;    Deformation;    Microstructure;    High-entropy alloys;    Plasticity;    Cryogenic temperatures;   

DOI  :  10.1016/j.msea.2020.139290

来源: Elsevier

【 摘 要 】

The current work compares the deformation behavior of CoCrFeMnNi and CoCrNi in the temperature interval between 295 K and 8 K through a series of quasi-static tensile tests. Temperature-dependent yield stress variation was found to be similarly high in these two alloys. Previous investigations only extended down to 77 K and showed that a small amount of epsilon-martensite was formed in CoCrNi while this phase was not observed in CoCrFeMnNi. The present study extends these investigations down to 8 K where similar low levels of epsilon-martensite were presently detected. Based on this result, a rough assessment has been made estimating the importance of deformation twinning to the strength. The relative work hardening rates of CoCrFeMnNi and CoCrNi were comparable in value despite the differences in e-martensite formation during deformation. CoCrFeMnNi deforms by dislocation slip and deformation twinning while deformation in CoCrNi is also accommodated by the formation of epsilon-martensite at cryogenic temperatures. Additionally, CoNi, a solid solution from the Co-Cr-Fe-Mn-Ni system with low strength, was used for comparison, showing contrasting deformation behavior at cryogenic temperatures.

【 授权许可】

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