Study of the Effect of Forced Convection by Electromagnetic Stirring on the Phase Change Process: Application on the Metallic Alloy Solidification

Abstract

As part of the PNE project (Program National Exceptional), this work aims to contribute to the development of a numerical tool predicting the influence of natural and forced convection on the phase change of pure metals and metallic alloys. The geometrical configuration considered throughout this study was chosen to correspond to the crucible of an experimental benchmark called 'AFRODITE', developed at the SIMAP-EPM laboratory in Grenoble/France. Different numerical models (2D and 3D) have been proposed to study different cases of solidification of pure metals and metallic alloys involving segregation phenomena. The 3D model, based on the enthalpy-porosity approach, has been applied to the case of pure tin solidification in order to study the effect of two types of dynamic configuration: purely thermal/natural convection and forced convection driven by an electromagnetic stirring generated by an external traveling magnetic field. Regarding the 2D model (based on threephase crystal growth kinetics) under thermosolutal convection, it has been developed in order to better understand, master and control the solidification process of metallic alloys, in terms of final crystal structure and the defects that occur during solidification, including segregation at the meso and macroscopic scales. The numerical models developed are validated by in-situ and real time measurements of temperatures at any point of the solidification system, which allows a quantitative and qualitative validation.