Comparison of martensite crystal profiles, calculated in a growth wave model and observed by experiment

Possible Wave Processes Controlling the Growth of Martensite Crystals at B2-B19, B2-B19' and B2-R Transformations

“…In our opinion, the exact fulfillment of the Bain OR would demonstrate that the conditions for material rotation of the lattice were not met in experiments with foils under examined conditions. In the general case, OR (11), (12) are preferable. [19], the B19′ phase can be formed directly from the B2 phase after (or simultaneously with) the B2-B19 and B2-R transitions.…”

“…For this purpose, it must be taken into account that the initial stage of forming the B19′ phase is associated with the influence of elastic fields of dislocations inherited by an intermediate mesoscopic state (IMS) after the B2 → IMS transition [30] or by the B19 phase after the B2 → B19 transition [31]. It was shown that dislocations change the orientation of the lines Λ by Λ′ due to strain of unit cells and of the lines Λ′ by Λ ′ ′ due to material rotation (12). As a result, the martensite crystals with the {0.78 0.39 0.48} B2 habit planes are associated with nucleation in elastic fields of dislocations with lines whose 10 Shape Memory Alloys: Properties, Technologies, Opportunities orientations Λ ′ ′ virtually coincide with the habit planes after strain and material rotation as it is evident from Table 1.…”

“…14. The description of the profiles of martensite crystals formed in a medium containing planar inhomogeneities [12,13]. 15.…”

Formation of martensite crystals in the limiting case of a supersonic growth rate

“…On the basis of equation system (11) one can also naturally describe the change in the profiles of martensite crystals growing in a spatially non-uniform medium [29][30][31] by introducing the dependence of the "effective" wave attenuations of controlling waves on coordinates. At the present time, the achieved completeness degree of the characteristic morphology description allows to a great extent to reconstruct, on the basis of the morphological attributes, the dynamic pattern of MT development, i.e.…”

Formation of martensitic crystals in the limiting case of supersonic growth speed

“…На базе системы уравнений (11) естественным образом можно описать и изменение профилей кристаллов мартенсита, растущих в пространственно-неоднородной среде [29][30][31], вводя зависимость от координат "эффективных" затуханий управляющих волн. В настоящее время достигнутая степень полноты описания характерной морфологии позволяет в значительной степени реконструировать по морфологическим признакам динамическую картину развития МП, т.е.…”