J. Phys. IV France
Volume 05, Numéro C8, Décembre 1995
International Conference on Martensitic Transformations – ICOMAT 95
Page(s) C8-157 - C8-160
International Conference on Martensitic Transformations

J. Phys. IV France 05 (1995) C8-157-C8-160

DOI: 10.1051/jp4:1995819

Precursor Shear Elastic Pseudo-Isotropy in Near Second Order Martensitic Phase Transitions

H.D. Chopra and M. Wuttig

Department of Materials and Nuclear Engineering, The University of Maryland, College Park, MD 20742-2115, U.S.A.

In contrast to the behavior of the isentropic elastic constants both isothermal constants, C' and C44, of In-Cd, In-Tl and Fe-Pd alloys soften on approaching the martensite start temperature. The isothermal, i.e. low frequency, ≈500Hz, anisotropy ratio approaches a value of unity as the martensitic transformation is approached from above. The parent phase becomes shear elastically pseudo-isotropic. Close to the transition, this shear pseudo-isotropy reflects the reorientation of incipient variants in the cubic phase under the influence of the dynamic measuring stress. It represents a true dynamical precursor of this fcc <-> fct near second order martensitic phase transition.

© EDP Sciences 1995