Please use this identifier to cite or link to this item:
http://hdl.handle.net/10397/106378
Title: | Superior high-temperature properties and deformation-induced planar faults in a novel L1₂-strengthened high-entropy alloy | Authors: | Zhao, YL Yang, T Li, YR Fan, L Han, B Jiao, ZB Chen, D Liu, CT Kai, JJ |
Issue Date: | 15-Apr-2020 | Source: | Acta materialia, 15 Apr. 2020, v. 188, p. 517-527 | Abstract: | We developed a novel high-performance L12-strengthened high-entropy alloy (HEA) in the multicomponent Ni-Co-Fe-Cr-Al-Nb system. The phase transformation, mechanical properties and associated deformation behaviors were systematically investigated through combinational analyses involving the three-dimensional atom probe tomography (3D-APT), transmission electron microscopy (TEM) and first-principles calculations. In contrast to conventional alloys that generally strengthened by Ni3(Al, Ti)-type precipitates, a high density of coherent L12 nanoprecipitates with a new chemical constitution of (Ni, Co, Fe, Cr)3(Al, Nb) can be controllably introduced via elaboratively tuning the content of Al and Nb, resulting in a large lattice misfit of ~0.78% that rarely achieved in previous HEAs. The newly developed (Ni2Co2FeCr)92Al4Nb4 HEA enables excellent tensile properties at a large temperature window from room temperature to 870 °C. More remarkably, an anomalous growth in yield strength can be observed at the temperatures above 600 °C, showing a peak yield stress over 720 MPa when deformed at 760 °C, which surpasses most of the previous L12-strengthened HEAs, as well as the commercial superalloys. Detailed TEM analyses revealed that the multicomponent L12 precipitates are mainly sheared by the super-partial dislocations, forming superlattice intrinsic stacking fault (SISF) loops coupled with antiphase boundaries (APBs). Such an interesting deformation substructure enables sustained work hardening and produces high tensile strengths at the high temperatures. The underlying mechanisms of those SISF loops were carefully discussed, which could be possibly ascribed to the local elemental segregation on the planner faults. | Keywords: | Deformation mechanisms High-entropy alloys High-temperature strength Planar faults |
Publisher: | Elsevier Ltd | Journal: | Acta materialia | ISSN: | 1359-6454 | EISSN: | 1873-2453 | DOI: | 10.1016/j.actamat.2020.02.028 | Rights: | © 2020 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved. © 2020. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/. The following publication Zhao, Y. L., Yang, T., Li, Y. R., Fan, L., Han, B., Jiao, Z. B., ... & Kai, J. J. (2020). Superior high-temperature properties and deformation-induced planar faults in a novel L12-strengthened high-entropy alloy. Acta Materialia, 188, 517-527 is available at https://doi.org/10.1016/j.actamat.2020.02.028. |
Appears in Collections: | Journal/Magazine Article |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
Fan_Superior_High-Temperature_Properties.pdf | Pre-Published version | 2.29 MB | Adobe PDF | View/Open |
Page views
5
Citations as of Jun 30, 2024
Downloads
1
Citations as of Jun 30, 2024
SCOPUSTM
Citations
150
Citations as of Jul 4, 2024
WEB OF SCIENCETM
Citations
141
Citations as of Jul 4, 2024
![](/image/google_scholar.jpg)
Google ScholarTM
Check
Altmetric
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.