Modelling of Phase Transformations in Titanium Alloys with a Phase-field Model

We have used a phase field model devoted initially to solidification for studying some phase transformations in metastable β titanium alloys. First calculations have been carried out to determine if we can rely on the model to get quantitative information on transformation kinetics. For a simple 1D problem, the phase field model, a sharp interface model and an analytical solution have been compared. The agreement was good even for quite coarse meshes. Then, 2D calculations have been done starting from micrographs of real microstructures. For a moderate departure from equilibrium, we obtained kinetics of the order of magnitude of some experimental measurements. For a larger departure and with the same parameters as before, the calculations failed because of the propagation of a spurious intermediate state, which could be avoided in decreasing drastically the mesh size.