Investigation of equiaxed dendritic alloy solidification by in-situ synchrotron X-radiography and phase-field modelling

Important aspects of alloy solidification is poorly understood due to lack of means to observe the microstructure formation processes in situ during solidification. A new method, developed by the applicant, for in-situ acquisition of high resolution sync hrotron X-radiograms will be used to obtain new knowledge on phenomena important in equiaxed dendritic alloy solidification. The new technique will be used to study growth of equiaxed dendrites in selected aluminium alloys. Advanced image processing rout ines, developed by the applicant will be used to extract morphological and constitutional data from the images. In cooperation with world leading expertise in modelling, these data will be used to advance predictive models for microstructure evolution in alloys. The specific subjects that will be given focus are: i) Free equiaxed growth in the transient mode, and the establishment of solute boundary layer. ii) Interactions between adjacent grains (with/without solid flow), how these interactions effect transport outside the envelope of interdendritic solute, and to what extent solid flow dilutes interdendritic solute from the grain envelope. iii) Establish to what extent the subjects above are decisive to the microstructure differences encountered in post solidified alloys of identical constitutions but with different levels of inoculation.