| About this Abstract |
| Meeting |
2025 TMS Annual Meeting & Exhibition
|
| Symposium
|
Accelerated Discovery and Insertion of Next Generation Structural Materials
|
| Presentation Title |
Combinatorial Discovery of Refractory Medium Entropy Alloys in Composition and Temperature Dimensions: Effect of Elements and Phase Transformation |
| Author(s) |
Changjun Cheng |
| On-Site Speaker (Planned) |
Changjun Cheng |
| Abstract Scope |
The variation in composition leads to significant changes in the structures and properties of medium-entropy alloys (MEAs) and high-entropy alloys (HEAs). The strategy based on combinatorial methodologies provided a solution for accelerated and high-throughput fabrication and characterization of the complex composition space. In this study, using magnetron co-sputtering and high-throughput annealing methods, we fabricated VI- and V-group MEA libraries with linear composition gradients. Based on synchrotron X-ray mapping results, (TiZr)xTa1-x alloy library exhibits fcc phase in Ta-rich region and nanocomposite structure with increasing TiZr composition; in contrast, (TiZr)xNb1-x and (TiZr)x(NbTa)1-x libraries show nanocrystalline bcc phase in the whole composition space. The fcc and nanocomposite structures underwent phase transformation to a fully crystalline bcc phase under annealing at 400 °C. The individual and synergistic effects of Nb and Ta are evaluated, and atomic resolution images and CALPHAD calculation further illustrate the phase transition processes and mechanisms. |
| Proceedings Inclusion? |
Planned: |
| Keywords |
High-Entropy Alloys, Phase Transformations, Thin Films and Interfaces |