| About this Abstract |
| Meeting |
MS&T24: Materials Science & Technology
|
| Symposium
|
High Entropy Materials: Concentrated Solid Solutions, Intermetallics, Ceramics, Functional Materials and Beyond V
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| Presentation Title |
Exploring Microstructural Evolution from Mesocrystal to Cube-Plate Dual Morphologies: Impact of Lattice Misfit and Elastic Moduli Variation during Spinodal Decomposition in Refractory HEAs |
| Author(s) |
Shiddhartha Ramprakash, Shalini Roy Koneru, Christopher Tandoc, Yong-Jie Hu, Hamish Fraser, Yunzhi Wang |
| On-Site Speaker (Planned) |
Shiddhartha Ramprakash |
| Abstract Scope |
The exceptional mechanical properties observed in AlMo0.5NbTa0.5TiZr and Al0.5NbTa0.8Ti1.5V0.2Zr alloys have been attributed to inverted superalloy-like BCC+B2 microstructure, characterized by cube-plate dual morphology. While it is widely acknowledged that these microstructures likely evolved through spinodal-assisted phase transformation pathways, the precise evolution of this morphology remains elusive. To address this gap, we employ phase-field method to simulate spinodally decomposed microstructures, focusing on a prototype Ti-W binary system where the nonlinear relationship between lattice misfit, elastic stiffness constants, and concentration mirrors typical behavior in refractory HEAs. Our simulation results elucidate the formation mechanism of plate-cube dual morphology through coarsening of mesocrystal-type two-phase microstructure that emerges during the early stages of spinodal decomposition. Furthermore, we systematically investigate key factors influencing mesocrystal and dual morphology evolution, including degree of asymmetry in the miscibility gap and strength of composition-dependent lattice misfit and modulus mismatch, to shed light on future microstructural engineering of multi-phase refractory HEAs. |