title: Complexion-mediated martensitic phase transformation in Titanium.
abstract: The most efficient way to tune microstructures and mechanical properties of metallic alloys lies in designing and using athermal phase transformations. Examples are shape memory alloys and high strength steels, which together stand for 1,500 million tons annual production. In these materials, martensite formation and mechanical twinning are tuned via composition adjustment for realizing complex microstructures and beneficial mechanical properties. Here we report a new phase transformation that has the potential to widen the application window of Ti alloys, the most important structural material in aerospace design, by nanostructuring them via complexion-mediated transformation. This is a reversible martensitic transformation mechanism that leads to a final nanolaminate structure of α″ (orthorhombic) martensite bounded with planar complexions of athermal ω (a-ω, hexagonal). Both phases are crystallographically related to the parent β (BCC) matrix. As expected from a planar complexion, the a-ω is stable only at the hetero-interface.
authors.affiliation: Max-Planck-Institut für Eisenforschung, Max-Planck-Strasse 1, 40237 Düsseldorf, Germany.|State Key Laboratory for Mechanical Behavior of Materials, Xi'an Jiaotong University, Xi'an 710049, China.
authors.forename: J
authors.initials: J
authors.lastname: Zhang
authors.affiliation: Department of Materials Science and Engineering, Massachusetts Institute of Technology,77 Massachusetts Avenue, Cambridge, Massachusetts 02139, USA.
authors.forename: C C
authors.initials: CC
authors.lastname: Tasan
authors.affiliation: Max-Planck-Institut für Eisenforschung, Max-Planck-Strasse 1, 40237 Düsseldorf, Germany.
authors.forename: M J
authors.initials: MJ
authors.lastname: Lai
authors.affiliation: Deutsches Elektronen-Synchrotron DESY, Notkestrasse 85, D-22607 Hamburg, Germany.
authors.forename: A-C
authors.initials: AC
authors.lastname: Dippel
authors.affiliation: Max-Planck-Institut für Eisenforschung, Max-Planck-Strasse 1, 40237 Düsseldorf, Germany.
authors.forename: D
authors.identifier: 0000-0003-0194-6124
authors.initials: D
authors.lastname: Raabe