Critical cooling rates for amorphous-to-ordered complexion transitions in Cu-rich nanocrystalline alloys
| Autor: | Charlette M. Grigorian, Timothy J. Rupert |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
010302 applied physics
Condensed Matter - Materials Science Materials science Polymers and Plastics Alloy Metals and Alloys Complexion Thermodynamics Materials Science (cond-mat.mtrl-sci) FOS: Physical sciences 02 engineering and technology engineering.material 021001 nanoscience & nanotechnology 01 natural sciences Nanocrystalline material Electronic Optical and Magnetic Materials Premelting Amorphous solid Grain growth 0103 physical sciences Ceramics and Composites engineering Grain boundary 0210 nano-technology Ternary operation |
| DOI: | 10.48550/arxiv.2008.00292 |
| Popis: | Amorphous complexions in nanocrystalline metals have the potential to improve mechanical properties and radiation tolerance, as well as resistance to grain growth. In this study, the stability of amorphous complexions in binary and ternary Cu-based alloys is investigated by observing the effect of cooling rate from high temperature on the occurrence of amorphous-to-ordered complexion transitions. Bulk Cu-Zr and Cu-Zr-Hf alloy samples were annealed to induce boundary premelting and then quenched through a procedure that induces a gradient of local cooling rate through the sample height. Amorphous complexion thickness distributions were found to be invariant to local cooling rate in the Cu-Zr-Hf alloy, demonstrating enhanced stability of the amorphous complexion structure compared to the Cu-Zr alloy, which had thinner amorphous complexions in the regions that were slowly cooled. The experimental results are used to construct time-temperature-transformation diagrams for the amorphous-to-ordered complexion transition in both the binary and ternary alloys, enabling a deeper understanding of the influence of cooling rate and grain boundary chemistry on complexion transitions. The critical cooling rate necessary to avoid complexion transitions in the ternary alloy is found to be at least three orders of magnitude slower than that for the binary alloy. |
| Databáze: | OpenAIRE |
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