About this Abstract |
Meeting |
2nd World Congress on High Entropy Alloys (HEA 2021)
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Symposium
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2nd World Congress on High Entropy Alloys (HEA 2021)
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Presentation Title |
Fabrication and Characterization of Nanoporous Multi Principal Element Alloy Thin Films by Vacuum Thermal Dealloying |
Author(s) |
Tibra Das Gupta, Taohid Bin Nur Tuhser, Maria Kosmidou, Michael J Detisch, Thomas John Balk |
On-Site Speaker (Planned) |
Tibra Das Gupta |
Abstract Scope |
Traditionally, nanoporous structures are made of single elements or binary alloys. Certain approaches for synthesizing these materials have been applied to multi principal element alloys (MPEAs), which are a combination of four or more elements that can impart enhanced phase stability. In this study, nanoporous MPEAs (np-MPEAs) were fabricated from magnesium-based refractory thin films (VMoNbTaMg and WVMoNbTaMg) that had been magnetron sputtered. A novel technique, vacuum thermal dealloying (VTD), which involves sublimation of higher vapor pressure element(s) from the precursor alloy, was employed for dealloying. When VMoNbTaMg and WVMoNbTaMg are heated under vacuum, the highest vapor pressure element (Mg) evaporates and creates a nanoporous structure. The np-MPEA exhibited an average ligament size of ~10 nm at 600˚C, indicating stability against coarsening at high temperature. XPS depth-profiling indicates that the VTD results in less alloy oxidation compared to traditional dealloying techniques. The effect of precursor film thickness will also be discussed. |
Proceedings Inclusion? |
Undecided |