Abstract
Phase transformations in a lamellar Ti–5Al–5Mo–5V–3Cr–1Zr (Ti-55531) alloy upon heating at continuous rates of 5, 20 and 100 °C/min has been studied by in situ high energy X-ray diffraction (HEXRD), aided by scanning and transmission electron microscopy, atom probe tomography and hardness measurements. During slow heating, the β phase has shown a behavior suggestive of additional transformations other than the continuous α → β decomposition observed at higher heating rates. Such behavior has been attributed to the precipitation of an embryonic isothermal ω phase. APT analyses have shown that no elemental partitioning occurs between the β matrix and the lamellar α phase, but it does between β and grain boundary α, suggesting that ω phase precipitates with solute rejection in regions outside lamellar colonies embedded in an enriched matrix. Above 500 °C, diffusion becomes significantly enhanced and α decomposition takes place.
Original language | English |
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Article number | 157105 |
Journal | Journal of Alloys and Compounds |
Volume | 853 |
DOIs | |
Publication status | Published - 5 Feb 2021 |
Keywords
- Atom probe tomography
- Element partitioning
- High energy X-ray diffraction
- Phase transformations
- Titanium alloys
ASJC Scopus subject areas
- Mechanics of Materials
- Mechanical Engineering
- Metals and Alloys
- Materials Chemistry
Fields of Expertise
- Advanced Materials Science