The strain distribution in a new generation nickel-based single crystal superalloy has been determined in the temperature range 293K–1598K. Measurements have been performed using diffraction of high energy synchrotron radiation (150keV, λ = 0.008 nm) to determine the variations with temperature of the γ/γ′ lattice mismatch and of the γ′ volume fraction. The chemical segregation at the dendrite scale and the internal stress induce a large range of values for the lattice mismatch. The measurements of the γ′ volume fraction determined by X-ray diffraction are in agreement with those obtained by atom probe tomography, image analysis or computation.
William Curtin, Céline Varvenne
Helena Van Swygenhoven, Steven Van Petegem, Nadine Baluc, Marina Garcia Gonzalez, Samy Hocine