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Center for Nonlinear Studies |
Structural transformations induced in solids by changing temperature or applying stress have been traditionally studied from a phenomenological point of view in metarials science. However, more recent approaches based on statistical mechanics provide a deeper understanding of such transitions. At the same time, the necessity of explaining new phenomena in materials opens new fundamental questions relevant to the statistical mechanics of non-equilibrium phase transitions, disordered systems, etc. In this talk I will consider the martensitic transformation (diffusionless solid-solid transformation) in metallic alloys as a particular example. I will give first a survey of experimental results in martensites revealing, for instance, intermittent behavior with power-law statistics and an intrinsic complexity comparable to that of turbulence, earthquakes, internet networks, and financial markets. I will then present a model explaining why such complexity and other related features emerge in martensites. The basis of the model is a continuous dynamical system on a rugged energy landscape, which in the quasistatic limit reduces to a self-organizing spin system formally equivalent to a sandpile automaton. http://www.lms.polytechnique.fr/users/perez/Perez-Reche.html
Host: Turab Lookman