Abstract:

Martensitic transformations are diffusion-less structural phase
transformations where the crystal structure changes by small
displacements of atoms, as opposed to long-range diffusion. Such
transformations are characterized by fascinating microstructures which
crucially influence the effective mechanical properties. The evolution
of this microstructure under an external stress also plays an important
role in the  "Shape Memory Effect". I will describe a Ginzburg-Landau
framework to study the microstructural evolution
in martensites and discuss how the approach can be used to study the
mechanical properties and the shape memory effect in single crystals as
well as polycrystals. I will also briefly discuss our recent work where
we have used the GL theory to understand the complex phase
transformations in steel.