Exceptional superelasticity via heterogeneity-driven texture optimization in equiaxed CuAlMn alloys
Achieving high superelasticity in polycrystalline shape memory alloys is fundamentally limited by strain incompatibilities arising from grain orientation. Realizing high martensitic transformation strain ( ${\varepsilon _{{\text{TS}}}}$ ) orientations that are favorable for superelasticity in equiax...
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| Main Authors: | , , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
IOP Publishing
2025-01-01
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| Series: | Materials Futures |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/2752-5724/adf3d1 |
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| Summary: | Achieving high superelasticity in polycrystalline shape memory alloys is fundamentally limited by strain incompatibilities arising from grain orientation. Realizing high martensitic transformation strain ( ${\varepsilon _{{\text{TS}}}}$ ) orientations that are favorable for superelasticity in equiaxed microstructures remains a major challenge. Here, a novel heterogeneity-driven texture optimization strategy is reported to enhance superelasticity in CuAlMn alloys through controlling high- ${\varepsilon _{{\text{TS}}}}$ orientations. Controlled deformation imprints dislocation density heterogeneity in differently oriented grains, leading to the gradients of sub-boundary energy. These gradients drive selective grain boundary migration, facilitating the preferential growth of grains with the high- ${\varepsilon _{{\text{TS}}}}$ <015> orientation. As a result, the fraction of <015>-oriented grains increases significantly from ∼19% to ∼70%, yielding a unprecedent tensile superelastic strain of ∼8.0% in equiaxed CuAlMn alloys, paving the way for practical engineering applications. This microstructural heterogeneity-guided strategy offers a general framework for overcoming texture-related limitations in polycrystalline functional materials. |
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| ISSN: | 2752-5724 |