Titanium alloys for structural applications

Ti alloys possess high specific strengths, excellent toughness and good corrosion resistance and are an excellent choice for many aerospace and biomedical applications. An even distribution of fine alpha precipitates is found to enhance the mechanical properties of beta-Ti alloys. One of the heterogeneous nucleation sites for alpha is the metastable omega phase. The research focus is to characterise the chemistry and structure, at an atomic-scale, during the phase evolution, to unveil the controverdial phase transformation mechanisms. The figure below shows that the Mo-lean regions, delineated by the Mo iso-concentration surfaces at 1.2 at%, facilitate the formation of the omega phase that is shown in the aberration-corrected TEM image.

Publications:

J. Ballor, T. Li, F. Prima, C.J. Boehlert, A. Devaraj; A review of the metastable omega phase in beta titanium alloys: the phase transformation mechanisms and its effect on mechanical properties, International Materials Reviews, (2022) 1-20.  Read more...

T. Li, M. Lai, A. Kostka, S. Salomon, S. Zhang, C. Somsen, M. Dargusch, D. Kent; Composition of the nanosized orthorhombic O' phase and its direct transformation to fine α during ageing in metastable β-Ti alloys, Scripta Materialia, 170 (2019), 183-188. Read more...

T. Li, D. Kent,  G. Sha, L.T. Stephenson, A.V. Ceguerra, S.P. Ringer, M.S. Dargusch, J.M. Cariney; New insights into the phase transformations to isothermal w and w-assisted a in near-ß alloys, Acta Mater. 106 (2016) 353-366. Read more...