Synchrotron Sub‐μ X‐ray Tomography of Kirkendall Porosity in a Diffusion Couple of Nickel‐Base Superalloy and Nickel after Annealing at 1250 °C

Kirkendall porosity that forms during interdiffusion in a diffusion couple of nickel-base superalloy CMSX-10 with pure nickel is investigated. The experiments are conducted at temperature 1250 °C, where the strengthening γ′-phase partially dissolved. studied by X-ray sub-μ tomography spatial resolution about 0.353 μm3 European Synchrotron Radiation Facility (ESRF) Grenoble, France. It found depending on distance from interface pores take different shapes: octahedral, rounded pyramidal, drop shaped, dendritic, pear and joint shapes. Such variety pore morphologies indicates complex multistage process nucleation growth under vacancy supersaturation degrees. experimental findings interpreted basis results modeling. shown kinetics essentially influenced dissolution γ′-phase.