Initial Excited State and Divergence of Wave Beams as Factors Responsible for the Realization of the Wave Process that Controls the Growth of Transformation Twins

• Published in: Physics of metals and metallography 2019-05, Vol.120 (5), p.422-428
• Main Authors: Kashchenko, M. P., Kashchenko, N. M., Chashchina, V. G.
• Format: Article
• Language: English
• Subjects: Analysis; Chemistry and Materials Science; Crystal growth; Deformation mechanisms; Divergence; Excitation; Fourier transforms; Growth; Longitudinal waves; Martensite; Martensitic transformations; Materials Science; Metallic Materials; S waves; Superposition (mathematics); Theory of Metals; Twins; Wave diffraction; Wave propagation
• ISSN: 0031-918X; 1555-6190
• DOI: 10.1134/S0031918X19050065

In the dynamic theory of martensitic transformations the wave mechanism of growth of martensite crystals is controlled by the overlap of wave beams of quasi-longitudinal (or longitudinal) waves that carry deformation of the “tension–compression” type in orthogonal directions. The appearance of wave beams is considered a consequence of the appearance of the initial excited (vibrational) states. The presence of the transformation twins is interpreted as the result of the matched propagation of relatively long-wave (l waves) and short-wave ( s waves) displacements. With the aid of the Fourier transforms, an analysis was performed of the influence of the diffraction divergence of a pair of orthogonal wave beams on the formation of a region of their superposition, including the limiting case of narrow beams with one of the transverse dimensions of the front less than λ/2, where λ is the wavelength. The connection of the distribution of the amplitudes of spatial harmonics with the configuration of the initial excited state is discussed.