Structure of Domains Formed upon Martensitic Transformations B2→B19 and B2→B19' in Alloys with a B2 Superstructure

摘要

An analysis of symmetry changes upon the structural B2–ISS2 phase transition with subsequent martensitic transformations into the B19 and B19' phases has been performed. An interrelation between the atomic displacements and the lattice deformation has been shown to exist. It has been established that the structures with longitudinal and transverse displacements have the same symmetry and can pass into one another via a twinning operation. A sequence of transformations of the tensor of lattice deformations consistent with the transformations of the atomic displacements has been obtained. It has been found that the operations that provide these transformations are the operations of twinning.