The role of martensite decomposition and β-stabilizer segregation to interfaces in Ti-6Al-4V with an initial dual-phase α+α' microstructure

Pfeffer N, Bezold A, Vollhüter J, Nagel O, Weiser M, Stark A, Neumeier S, Höppel HW (2026)

Publication Type: Journal article

Publication year: 2026

Journal

Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing Elsevier

Book Volume: 959

Article Number: 150024

DOI: 10.1016/j.msea.2026.150024

Abstract

The strength of dual-phase α+α' Ti-6Al-4V sheet material can be significantly enhanced through additional short-time annealing lasting only a few minutes, as shown in previous work and attributed to nano-scale microstructural changes within the martensitically transformed β-phase. However, the microstructural mechanisms remained unclear. In this study, the microstructures of the as-received state, the solution heat treated state with α+α' microstructure and additionally (short-time) annealed states were compared to provide deeper insight into these microstructural processes. Advanced high-resolution techniques, including high resolution scanning transmission electron microscopy, atom probe tomography and high-energy X-ray diffraction, were combined with tensile testing for mechanical assessment. Short-time annealing of metastable Ti-6Al-4V α+α' microstructures at 570 °C for 180 s triggered an α' → α+β transformation, comprising: (i) chemical changes, involving V- and Fe-segregation to interfaces, and the formation of V-/Fe-enriched clusters; and (ii) crystallographic decomposition, manifested by α' lattice relaxation and lattice parameter changes. With prolonged annealing, element partitioning and β precipitation progressed from the clusters and nuclei located along interfaces, accompanied by slight changes in the lattice parameters of both phases. After 3 h, the microstructure approached equilibrium, with stabilized α and β phase fractions and lattice parameters. The strengthening achieved by short-time annealing is attributed to suppression of reorientation-induced plasticity in prior α'-martensite and dislocation-cluster/precipitate/solute interactions. In summary, this work reveals microstructural evolution and processes during martensite decomposition in dual-phase Ti-6Al-4V, including β-stabilizer segregation to interfaces. Further, it discusses their role in strength enhancement, providing guidance for developing effective heat treatment and processing routes.

Authors with CRIS profile

Nina Pfeffer Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften) Jan Vollhüter Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften) Oliver Nagel Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften) Martin Weiser Lehrstuhl für Werkstoffwissenschaften (Korrosion und Oberflächentechnik) (LKO) Steffen Neumeier Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften) Heinz Werner Höppel Lehrstuhl für Werkstoffwissenschaften (Allgemeine Werkstoffeigenschaften)

Involved external institutions

Helmholtz-Zentrum Hereon DE Germany (DE) Ohio State University US United States (USA) (US)

How to cite

APA:

Pfeffer, N., Bezold, A., Vollhüter, J., Nagel, O., Weiser, M., Stark, A.,... Höppel, H.W. (2026). The role of martensite decomposition and β-stabilizer segregation to interfaces in Ti-6Al-4V with an initial dual-phase α+α' microstructure. Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing, 959. https://doi.org/10.1016/j.msea.2026.150024

MLA:

Pfeffer, Nina, et al. "The role of martensite decomposition and β-stabilizer segregation to interfaces in Ti-6Al-4V with an initial dual-phase α+α' microstructure." Materials Science and Engineering A-Structural Materials Properties Microstructure and Processing 959 (2026).

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