The book is mainly devoted to the thermomechanical behavior of materials during solid-solid phase transformations. The physical mechanisms including diffusion, martensitic transformation and plasticity are described from material science point of view. The global behaviour is deduced from methods of classical as well as irreversible thermodynamics and continuum and micro mechanics. Mainly metals, both non ferrous and ferrous alloys but also geological problems are dealt with.Special attention is given to transformation induced plasticity and shape memory alloys. Three chapters are concerned with practical applications (heat treatment, smart structures, residual stresses).