The martensitic transformation in In-Tl alloys revisited.

Thumbnail Image
Journal Title
Journal ISSN
Volume Title
Australian Institute of Physics
The traditional view for the martensitic transformation in In-xat%Tl alloys, for 15.5 ≤ 𝑥 ≤ 30.5 was via a double shear such as: (101) [101]; (011) [011], on the basis of optical microscopy observations and measurements of the (𝑐11 - 𝑐12)/2 elastic constant. However, this model was called into question following recent low-ζ measurements of the [ζζ0][ζζ0] phonons. An alternative model for the formation of coherent nuclei and growth along conjugate {111} planes was once proposed by Geisler. This model is consistent with some electron diffuse scattering data as well as yielding identical x-ray pole figure results as those for the double-shear mechanism. Appropriate nuclei could be generated by 〈111〉 〈112〉 atomic displacements. To test such an idea we have measured the [ζζζ]T phonon branch for a good quality In-Tl crystal in a recent experiment using the cold-triple axis facility, SIKA, at the OPAL Research Reactor. These results will be reported and compared with the predictions of a model for the dynamical behaviour of coherent interfaces and modulated structures based on topological solitons, first introduced by Barsch and Krumhansl and applied to the twins accompanying martensitic transformations.
Alloys, Australia, OPAL Reactor, Coherent scattering, Diffraction, Scattering, Iron alloys, Iron base alloys, Martensitic steels
Finlayson, T. R., McIntyre, G. J., Rule, K. C., & Saxena, A. (2019). The martensitic transformation in In-Tl alloys revisited. Poster presented to the 43rd Annual Condensed Matter and Materials Meeting, Charles Sturt University, Wagga Wagga, NSW, 5th February - 8th February, 2019, (pp. 67). Retrieved from: