Evaluation of gamma prime volume fractions and lattice misfits in a nickel base superalloy using the external standard X-ray diffraction method

The unconstrained lattice parameters and volume fractions of γ′ for a low misfit nickel based superalloy were evaluated using X-ray diffraction techniques. Extraction techniques were used to provide unconstrained γ′ powders for both water quenched and slow cooled samples that were aged at 760 °C for 0, 25, 50, 100, and 200 h. The external standard method was used to determine the volume fraction for the unaged water quenched sample and the slow cooled sample aged for 200 h. These two extremes in processing conditions provided an increase in the total volume fraction of γ′.