In-situ investigation of strain and defect formation during Ni-base alloy solidification

A major issue during turbine blade production for aeronautic applications is the formation of defects such as stray grains, freckles, and segregated areas.These defects are linked to the development of strain and convective flows during the solidification step. The aim of the proposed experiments is to study in-situ misorientations occurring during the dendritic microstructure formation and fragmentation in metal alloys. The experiment will consist in visualizing the solidification of samples of a commercial Ni-base alloy and a model binary alloy for comparison with numerical simulations. To achieve this goal, directional solidification experiments will be monitored with a unique high-temperature furnace allowing time-resolved synchrotron radiography and diffraction imaging to be concomitantly used.