Microscopic Modeling and Simulation Of Martensite/Austenite Phase Transformations In Shape Memory Alloys

A sound understanding of the austenite/martensite transformation of shape memory alloys, either stress or temperature induced, must face the complex nucleation, evolution and interaction of martensite variants and dislocations. After the pioneering analytical theories of Ball and James [1,2] a small but increasing number of scientific groups are addressing this fascinating subject also, and mainly, from a numerical point of view. In this presentation a review of the methods application to simulate the martensite/Austenite transformation, most of which based on Phase Field, will be proposed. Our model will be compared to other approaches. Examples of the model application will be shown, in particular martensite evolution during stress induced transformation on a rectangular single crystal Shape Memory Alloy sample will be shown. The effect of model parameters, crystal orientation and static defects (like dislocation loops) introduction on the transformation will be addressed. [1] Ball, J.M. and James, R.D., Fine Phase Mixtures as Minimizers of Energy, Arch. Rat. Mech. Anal.100, 13-52 (1987). [2] Ball, J.M. and James, R.D., Proposed Experimental Tests of a Theory of Fine Microstructure, Phil. Trans. Royal Soc. London 338A, 389-450 (1992).