Homogenization of multicomponent alloys via partial melting

A practically important case, when homogenization of multicomponent alloys is achieved through partial melting, is analyzed. In the course of this process, liquid pools, initially formed from interdendritic material after re-heating, shrink continuously, change their composition, and finally disappear to leave an inhomogeneous solid solution behind. To tackle this diffusion-controlled isothermal process, a comprehensive mathematical model was developed to couple thermodynamic properties and kinetic characteristics. In particular, a numerical solution of the transient liquid phase problem for the multicomponent case is presented.The model was applied to simulate homogenization processes in Cu-Ni-Sn commercial alloys. Since the validity of quantitative estimations and predictions obtained with this model depend on the reliability of input thermodynamic information, the properties of the liquid and FCC phases in the Ni-Sn and Cu-Ni-Sn systems were re-assessed using the CALPHAD method.