J. Phys. IV France 05 (1995) C8-157-C8-160
Precursor Shear Elastic Pseudo-Isotropy in Near Second Order Martensitic Phase TransitionsH.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