Determination of single-crystal elastic constants from a cubic polycrystalline aggregate

A method for determining cubic stiffness constants from polcrystalline Young's modulus and X-ray elastic constants is described. The relations used among these elastic constants are those based on Kröner's quasiisotropic model. The X-ray elastic constants required [S₁(hkl)] are obtained by measuring various (hkl) d spacings of a stressed specimen under symmetric θ–2θ scan mode. An application to an Fe–31Ni alloy has given the results: C₁₁ = 1.47, C₁₂ = 1.05 and C₄₄ = 1.24 × 10¹¹ Pa.