Crystal dynamics of the BCC-HCP martensitic transformation: II. Morphology

Abstract

A dynamic theory of the formation of martensite crystals upon the bcc-hcp transformation based on the concepts of the heterogeneous nucleation and related controlling wave process is presented. It is shown that the entire set of the observed morphological characteristics is unambiguously connected with the trajectory of the martensitic reaction assigned by the controlling wave process. In particular, for the orientation relationships between the phases involved in the transformation there was found an analytical dependence of the angle between the directions of close-packed atomic rows on the elastic properties of the initial bcc lattice. Quantitative estimates are given based on the values of the elastic moduli for bcc titanium. A discussion of the results obtained is conducted and special attention is paid to the new possibilities of experimental studies. © 2008 Pleiades Publishing, Ltd.