Mobile martensitic microstructures in single crystals of shape memory alloys: from experimental observations to mathematical modelling
- Hanuš Seiner (Institute of Thermomechanics AS CR, Prague)
Shape memory alloys (SMAs) are smart materials able to undergo diffusionless martensitic transitions upon thermal or mechanical loadings. At the level of a single crystal, these transitions are provided by formation and propagation of mobile interfaces or interfacial microstructures (object composed of more mobile interfaces). Experimental observations of these objects and their consequent analyses by theoretical tools and numerical models enable a deeper insight into the macroscopic effective behaviour of SMAs, and improve the understanding of the underlying physical phenomena.
The talk will be focused on mobile microstructures in two particular SMAs: Cu-Al-Ni undergoing the cubic-to-orthorhombic transition and Ni-Mn-Ga undergoing the cubic-to-tetragonal transition with adaptive monoclinic modulations. For both alloys, the constructions of theoretical and numerical models of experimentally observed microstructures will be described, and the resulting models will be discusses with the emphasis on their contribution to understanding the mechanisms of transitions in SMAs.