Micromechanical modeling and calculation for diffraction elastic constants of Ni-based superalloy

A micromechanical model for Ni-based superalloys with reinforcement γ′-Ni3(AlTi) was established to investigate the elastic modulus related to crystallographic directions. In this model, grains were assumed to have spheroidal random dispersion, and the interface of matrix and inclusion phases with lattice strain and macroscopic stress being assumed were straightforwardly converted. Introducing a representative volume element, a series of micromechanical averaged field equations administrating diffraction elastic constants of the γ-(Ni–Cr–Fe) matrix phase and the γ′-Ni3(AlTi) dispersed particulate phase are presented to render qualitative and quantitative analysis in terms of scale transition formalism, respectively. Following the content of the micromechanical framework, the effective elastic properties of Ni-based superalloys were predicted. Furthermore, the numerical diffraction elastic constants of several diffraction planes were compared with those of experimental determination by neutron diffraction, whose implications of diffraction elastic constants required for experimental measurement of residual stresses were discussed.