The effect of γ'-precipitates on the strain field in Ni-based superalloys: an in situ study using dark-field X-ray microscopy

One issue with nickel-based superalloys is that the formation of intragranular precipitates can lead to strain-age cracking of components when used at elevated temperatures. The exact mechanisms responsible for such failures are not fully understood. One hypothesis is that the cracks form due to tensile stresses building up in the interior of grains due to the different thermal expansion coefficients of the precipitates and the matrix grain. We will investigate the evolution of such stress fields in 3D using dark-field x-ray microscopy during high temperatures ageing of nickel-based superalloys.