Microstructural modelling of rapidly solidified droplets and spray formed strip of Al-Cu-Sc – MIMOSA

Solidification of alloys is a complex phenomenon arising in many modern experimental techniques and industrial technologies related to casting and surfaces processing. The variation of different conditions of solidification (such as undercooling or cooling rate) gives a possibility to control the morphology and size of crystal structure, which substantially influence physical and chemical properties of alloys. In particular, deep undercooling of alloys below equilibrium liquidus, and eutectics results in rapid solidification and yields materials with improved mechanical, magnetic and electrical properties.
The proposed 3 year project is a collaboration between Canada and France involving three teams of researchers. We will generate powder and spray formed samples using Impulse Atomization (IA) - a single fluid rapid solidification technique (Canada). Al-Cu(Sc) alloys will be generated. The latter is expected to be supersaturated in the alpha matrix due to undercooling. Pilot tests on strip casting will also be carried out at Novelis. The solidified samples will be characterized using SEM, X-Ray diffraction, differential scanning calorimetry and microhardness (Canada). In addition, state of the art characterization such as 3D-micro and nano-tomography and Neutron Diffraction will be carried out (Canada and France). The Collaborators all have experience in these areas as well as have been working together for over a decade. Finally, the internal dendritic structure and the shrinkage porosity of a rapidly solidified droplet and skin of the cast strip will be modeled using the level set method (France). The characterization data collected will be used to verify the models.
We will provide a basis for understanding the solidification structure resulting from casting processes such as strip casting, rheo-casting and spray deposition where cooling rates and heat fluxes are similar to IA. The proposed alloy systems are important for automotive applications where Canada plays a major role in production and manufacturing. Two graduate students and one undergraduate will be trained in Canada.