Giant thermal expansion and α-precipitation pathways in Ti-Alloys

Author(s)

Matthias Boenisch, Ajit Panigrahi, Mihai Stoica, Mariana Calin, Eike Ahrens, Michael Zehetbauer, Werner Skrotzki, Juergen Eckert

Abstract

Ti-Alloys represent the principal structural materials in both aerospace development and metallic biomaterials. Key to optimizing their mechanical and functional behaviour is in-depth know-how of their phases and the complex interplay of diffusive vs. displacive phase transformations to permit the tailoring of intricate microstructures across a wide spectrum of configurations. Here, we report on structural changes and phase transformations of Ti-Nb alloys during heating by in situ synchrotron diffraction. These materials exhibit anisotropic thermal expansion yielding some of the largest linear expansion coefficients (+ 163.9×10

^-6 to-95.1×10

^-6 °C

^-1) ever reported. Moreover, we describe two pathways leading to the precipitation of the α-phase mediated by diffusion-based orthorhombic structures, α″

_lean and α″

_iso. Via coupling the lattice parameters to composition both phases evolve into α through rejection of Nb. These findings have the potential to promote new microstructural design approaches for Ti-Nb alloys and β-stabilized Ti-Alloys in general.

Organisation(s)

Physics of Nanostructured Materials

External organisation(s)

Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden, Technische Universität Dresden, Montanuniversität Leoben, Österreichische Akademie der Wissenschaften (ÖAW), Institute of Minerals and Materials Technology

Journal

Nature Communications

Volume

No. of pages

ISSN

2041-1723

DOI

https://doi.org/10.1038/s41467-017-01578-1

Publication date

11-2017

Peer reviewed

Yes

Austrian Fields of Science 2012

103018 Materials physics

Keywords

ASJC Scopus subject areas

Physics and Astronomy(all), Chemistry(all), Biochemistry, Genetics and Molecular Biology(all)

Portal url

https://ucrisportal.univie.ac.at/en/publications/giant-thermal-expansion-and-precipitation-pathways-in-tialloys(78c98f1b-79cb-488b-a01f-d88c8e16a27c).html