ESOMAT 2009, 03006 (2009)
DOI: 10.1051/esomat/200903006

FEM Mo delling of Elastically Strained Interfacial Microstructures in Cu-Al-Ni Single Crystals

Ondřej Glatz^{1, 2}, Hanuš Seiner^{1, 2} and Michal Landa<sup>1

1</sup>  Institute of Thermomechanics, Academy of Sciences of the Czech Republic, Dolejškova 5, 182 00 Prague 8, Czech Republic.
²  Faculty of Nuclear Sciences and Physical Engineering, Czech Technical University in Prague, Trojanova 13, 120 00 Prague 2, Czech Republic.

hseiner@it.cas.cz

Published online: 1 September 2009

Abstract
In this paper, a construction of FEM models of particular microstructures forming between austenite and mechanically stabilised 2H-martensite of the Cu-Al-Ni shape memory alloy is presented. Since these microstructures appearing during the shape recovery process (the so-called X-interfaces or the Xmicrostructures) are not global minimisers of the free energy, their mesoscopic morphology cannot be determined from any known thermodynamic extremal criterion, but must be taken directly from the experimental observations. For the elastic coefficients of both austenite and martensite phase of this alloy known from the ultrasonic measurements, such model enables determination of elastic strains within the microstructure and, thus, evaluation of the stored elastic energy in the microstructure. The model (implemented in COMSOL Multiphysics FEM environment) is applied to analyse interfacial microstructures observed experimentally in a prismatic bar of a single crystal of the examined alloy, and to find optimal morphology of this microstructure by means of the free energy (local) minimisation.

© Owned by the authors, published by EDP Sciences 2009