Domain walls and transverse shock waves in shape-memory alloys

Abstract

The martensitic phase transition in shape-memory alloys which is responsible for their ferroelastic and pseudoelastic deformation behaviour is described by a one-dimensional Landau theory. Domain walls between Martensite variants and between Austenite and Martensite are modelled as transverse shock waves. From the balance of momentum and of energy the jump of temperature across and the speed of the domain walls are calculated. The direction of motion follows from the entropy principle. Under certain conditions a moving domain wall acts like a heat engine converting free energy into mechanical work.