Extreme Expansion and Reversible Hydrogen Solubility in h.c.p. Titanium Stabilized by Colossal Interstitial Alloying

Frederik B. Kværndrup*, Marcel A.J. Somers, Thomas L. Christiansen

*Corresponding author for this work

    Research output: Contribution to journalJournal articleResearchpeer-review

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    Titanium and its alloys could be called the “streetwalker” among commercially applied metals, because its poor nobility allows it to “pick-up” anything. Titanium is one of the metals that forms very stable borides, carbides, nitrides, oxides, and even hydrides. The solubility of nitrogen and oxygen in the hexagonal crystal structure of (metallic) titanium is very high; on the other end limited quantities of boron, carbon, and hydrogen can be dissolved. In the present contribution, we report on a significant increase in the solid solution limit of hydrogen in hexagonal close-packed (h.c.p.) titanium, where the h.c.p. crystal lattice is stabilized by deliberate interstitial alloying with high quantities of nitrogen or oxygen atoms. The presence of nitrogen/oxygen prevents the hydrogen-induced transformation of the h.c.p. titanium lattice to a face-centered cubic (f.c.c.) titanium lattice that occurs if no oxygen or nitrogen is present. The hydrogen content that can be accommodated at room temperature in h.c.p. titanium is as high as an unprecedented 50 at. pct from about 0 at. pct and causes an anisotropic expansion of the hexagonal lattice. This finding showcases that there could be an unexploited potential for combining large quantities of interstitials in titanium-based lattices.
    Original languageEnglish
    JournalMetallurgical and Materials Transactions A: Physical Metallurgy and Materials Science
    Pages (from-to)4997–5003
    Publication statusPublished - 2021

    Bibliographical note

    Please not correction: https://link.springer.com/article/10.1007%2Fs11661-021-06553-6

    After publication of this article the first sentence of the abstract was changed by the authors to read "Titanium and its alloys are very reactive and have a high affinity to interstitial elements.” The original sentence contained inappropriate language. Neither Metallurgical and Materials Transactions A nor the publisher in any way endorse the use of this language.


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