Matrix description of martensitic crystals self-accommodation in alloys with shape memory effects

The paper presents a method of classification of self-accommodation complexes, combining group analysis with the minimization of the deformation of the form. During the phase transformation of the martensitic type, the unit cells of the austenite and martensitic lattice are transformed into each other by homogeneous deformation, which, when applied to the sphere of radius equal to one, turns it into a three-axis ellipsoid (ellipsoid of deformation). Twinning of the martensite lattice changes the ellipsoid equation in accordance with the coordinate transformation. By summing the ellipsoid equation for several twins, one can get an idea of the strain averaged over domains and estimate the total form change of the self-accommodating complex.