Peritectic transformations are essential for the production of steels. In this project we investigate solidification from the melt, using sharp interface and phase field methods.
Although of large interest for applications, basic growth laws for associated scenarios in peritectic transformations are yet quite untouched on the level of scaling laws. However, such laws are essential for a general and semi-analytical understanding, going beyond specific phase-field like simulations. For peritectic systems, the variety of observed growth modes is large due to the nature of the phase diagram of peritectic systems, especially when considering directional solidification as it appears in many industrial production chains. The presence of the thermal gradient in directional solidification precludes the presence of solid phases in large distances in front of the propagating phase interfaces, and similar for liquid phases far behind; in this sense directional peritectic solidification is richer and far less understood than e.g. eutectic growth. We aim at the prediction of the scaling behaviour of velocities and length scales that appear in different growth configurations as they have been recently observed experimentally.
We study different growth morphologies during peritectic solidification. In particular, we investigate dendritic growth as a result of the peritectic reaction, and compare this case to coupled cellular growth. The latter is of practical interest for the formation of composite materials directly during casting, as shown for Fe-Ni. We find that depending on the spacing of the primary solidification a morphological transition between dendritic and cellular growth occurs.