Partially recrystallized microstructures expand the strength-toughness envelope of CrCoNi medium-entropy alloy

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68081723%3A_____%2F24%3A00602479" target="_blank" >RIV/68081723:_____/24:00602479 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.nature.com/articles/s43246-024-00704-z" target="_blank" >https://www.nature.com/articles/s43246-024-00704-z</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1038/s43246-024-00704-z" target="_blank" >10.1038/s43246-024-00704-z</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Partially recrystallized microstructures expand the strength-toughness envelope of CrCoNi medium-entropy alloy

Popis výsledku v původním jazyce

Engineering materials exhibit an undesirable tradeoff between strength and resistance to crack propagation (fracture toughness). Here we demonstrate how this tradeoff can be circumvented by thermo-mechanical processing that produces a partially recrystallized, heterogeneous microstructure. An equimolar CrCoNi alloy was forged at room temperature (298 K) to produce high densities of three-dimensional crystallographic defect networks. Post-deformation heat treatments caused localized recrystallization that resulted in a bimodal microstructure with hard, non-recrystallized grains and soft, recrystallized grains. In this condition, the yield strength at 298 K is 2.75x the values previously obtained for the same alloy in the fully recrystallized state while the fracture toughness remains the same. The yield strength is further enhanced at 77 K without compromising the fracture toughness. This outstanding strength-toughness combination at 77 K exceeds those reported for other metallic materials and appears to result from the composite nature of the microstructure with non-recrystallized grains providing strength and recrystallized grains enabling plasticity that dissipates stresses during crack propagation. Our findings indicate that by tuning the degree of recrystallization through thermomechanical processing techniques, it will be possible to further expand the envelope bounding the strength and toughness of a range of structural metals at engineering component scales.

Název v anglickém jazyce

Partially recrystallized microstructures expand the strength-toughness envelope of CrCoNi medium-entropy alloy

Popis výsledku anglicky

Engineering materials exhibit an undesirable tradeoff between strength and resistance to crack propagation (fracture toughness). Here we demonstrate how this tradeoff can be circumvented by thermo-mechanical processing that produces a partially recrystallized, heterogeneous microstructure. An equimolar CrCoNi alloy was forged at room temperature (298 K) to produce high densities of three-dimensional crystallographic defect networks. Post-deformation heat treatments caused localized recrystallization that resulted in a bimodal microstructure with hard, non-recrystallized grains and soft, recrystallized grains. In this condition, the yield strength at 298 K is 2.75x the values previously obtained for the same alloy in the fully recrystallized state while the fracture toughness remains the same. The yield strength is further enhanced at 77 K without compromising the fracture toughness. This outstanding strength-toughness combination at 77 K exceeds those reported for other metallic materials and appears to result from the composite nature of the microstructure with non-recrystallized grains providing strength and recrystallized grains enabling plasticity that dissipates stresses during crack propagation. Our findings indicate that by tuning the degree of recrystallization through thermomechanical processing techniques, it will be possible to further expand the envelope bounding the strength and toughness of a range of structural metals at engineering component scales.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

20501 - Materials engineering

Projekt

<a href="/cs/project/GM24-11058M" target="_blank" >GM24-11058M: Design a optimalizace 3D tisknutelných slitin s více hlavními prvky zpevněných oxidickou disperzí pro extrémní prostředí</a><br>

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2024

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Communications Materials

ISSN

2662-4443

e-ISSN

2662-4443

Svazek periodika

5

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

10

Strana od-do

263

Kód UT WoS článku

001369679000002

EID výsledku v databázi Scopus

2-s2.0-85211367819