Abstract
The thermal stability of ultrafine-grained metals can be fully understood when observing time-resolved microstructural changes over multiple-length scales. The global microstructural relaxation behavior upon heating of an ultrafine-grained (UFG) CoCrFeNi high-entropy alloy (HEA) was characterized by in-situ heating neutron diffraction measurements. Before heating, the nanocrystalline microstructure was introduced by applying high-pressure torsion (HPT), leading to severe lattice distortion by excess dislocations and defects. The sequential information on the structural relaxation of recovery, recrystallization, and grain growth are identified by in-situ heating neutron diffraction analysis defining the texture development, linear thermal lattice expansion, and stress relaxation behaviors of the UFG HEA with increasing temperature up to 1300K. By contrast, nanocrystalline metals processed by HPT are often inhomogeneous microstructurally and compositionally. The influence of such inhomogeneity on the macro-scale microstructural relaxation is monitored using an HPT-processed CoCrFeNiMn high-entropy alloy through in-situ heating laser-scanning confocal microscopy. This study emphasizes the importance of characterization techniques for further in-depth exploration of the SPD-processed ultrafinegrained structure.
Original language | English |
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Title of host publication | ICSAM 2023 - 14th International Conference on Superplasticity in Advanced Materials |
Editors | Jose-Maria Cabrera |
Publisher | Association of American Publishers |
Pages | 235-243 |
Number of pages | 9 |
ISBN (Print) | 9781644902608 |
DOIs | |
State | Published - 2023 |
Externally published | Yes |
Event | 14th International Conference on Superplasticity in Advanced Materials, ICSAM 2023 - Barcelona , Spain Duration: Jul 10 2023 → Jul 12 2023 |
Publication series
Name | Materials Research Proceedings |
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Volume | 32 |
ISSN (Print) | 2474-3941 |
ISSN (Electronic) | 2474-395X |
Conference
Conference | 14th International Conference on Superplasticity in Advanced Materials, ICSAM 2023 |
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Country/Territory | Spain |
City | Barcelona |
Period | 07/10/23 → 07/12/23 |
Funding
This study was supported in part by the National Science Foundation of the United States under Grant No. CMMI-2051205 (M.K.). The authors greatly acknowledge the Ibaraki prefectural government and the J-PARC facility for granting access to iMATERIA under the 2019 Overseas Academic User Program of Ibaraki Neutron Beamline BL20, proposal number 2019PM2014. The authors acknowledge the University of Wollongong for granting access to facilities in the High-temperature Microscopy Laboratory. This study was supported in part by the National Science Foundation of the United States under Grant No. CMMI-2051205 (M.K.). The authors greatly acknowledge the Ibaraki prefectural government and the J-PARC facility for granting access to iMATERIA under the 2019 Overseas Academic User Program of Ibaraki Neutron Beamline BL20, proposal number 2019PM2014. The authors acknowledge the University of Wollongong for granting access to facilities in the Hightemperature Microscopy Laboratory.
Keywords
- High-Pressure Torsion
- Laser-Scanning Confocal Microscopy
- Nanostructure
- Neutron Diffraction
- X-Ray Diffraction