Bidirectional Transformation Enables Hierarchical Nanolaminate Dual-Phase High-Entropy Alloys
© 2018 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim.
| Veröffentlicht in: | Advanced materials (Deerfield Beach, Fla.). - 1998. - 30(2018), 44 vom: 27. Nov., Seite e1804727 |
|---|---|
| 1. Verfasser: | |
| Weitere Verfasser: | , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2018
|
| Zugriff auf das übergeordnete Werk: | Advanced materials (Deerfield Beach, Fla.) |
| Schlagworte: | Journal Article dual phase hierarchical nanolaminate structures high‐entropy alloys phase transformation scanning transmission electron microscopy |
| Zusammenfassung: | © 2018 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim. Microstructural length-scale refinement is among the most efficient approaches to strengthen metallic materials. Conventional methods for refining microstructures generally involve grain size reduction via heavy cold working, compromising the material's ductility. Here, a fundamentally new approach that allows load-driven formation and permanent refinement of a hierarchical nanolaminate structure in a novel high-entropy alloy containing multiple principal elements is reported. This is achieved by triggering both, dynamic forward transformation from a faced-centered-cubic γ matrix into a hexagonal-close-packed ε nanolaminate structure and the dynamic reverse transformation from ε into γ. This new mechanism is referred to as the "bidirectional transformation induced plasticity" (B-TRIP) effect, which is enabled through a near-zero yet positive stacking fault energy of γ. Modulation of directionality in the transformation is triggered by local dissipative heating and local micromechanical fields. The simple thermodynamic and kinetic foundations for the B-TRIP effect render this approach generally suited for designing metastable strong and ductile bulk materials with hierarchical nanolaminate substructures |
|---|---|
| Beschreibung: | Date Completed 03.01.2019 Date Revised 01.10.2020 published: Print-Electronic Citation Status PubMed-not-MEDLINE |
| ISSN: | 1521-4095 |
| DOI: | 10.1002/adma.201804727 |