Impurity and texture driven HCP-to-FCC transformations in Ti-X thin films during in situ TEM annealing and FIB milling
| Autor: | Josh Kacher, Ruopeng Zhang, Paul A. J. Bagot, Andrew M. Minor, James O. Douglas, Rachel Traylor |
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| Jazyk: | angličtina |
| Rok vydání: | 2020 |
| Předmět: |
010302 applied physics
Materials science Polymers and Plastics Annealing (metallurgy) Metals and Alloys Analytical chemistry Titanium hydride chemistry.chemical_element 02 engineering and technology Atom probe 021001 nanoscience & nanotechnology 01 natural sciences Focused ion beam Electronic Optical and Magnetic Materials law.invention chemistry.chemical_compound chemistry Transmission electron microscopy Impurity law 0103 physical sciences Ceramics and Composites Thin film 0210 nano-technology Titanium |
| Popis: | A hexagonal close-packed (HCP) to face-centered cubic (FCC) phase transition has been observed in freestanding alpha-titanium (α-Ti) thin foils under two separate conditions: (1) after focused ion beam (FIB) irradiation, and (2) during in situ heating in a transmission electron microscope (TEM). The FCC phase is not found on the Ti single-component equilibrium phase diagram, however, both FCC structures were found to be stable after formation under these conditions. Here, we combine analytical TEM and Atom Probe Tomography (APT) investigations into the chemical nature of these anomalous FCC Ti-X phases. Both occurrences of the FCC phase were observed in thin films containing (initial) prismatic HCP surface plane texturing and appear to be facilitated by hydrogen and oxygen impurities. Our results suggest that the FIB-induced FCC Ti-X is a form of titanium hydride (δ-TiH2 and/or γ-TiH), while the thermally-induced FCC Ti-X appears to be tied to the incorporation of oxygen. |
| Databáze: | OpenAIRE |
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