Elastic properties of high-temperature intermetallics

Abstract

Methods to determine the elastic constants (EC) of high-temperature intermetallics are reviewed. The standard method to measure Ecs of single crystals is the pulse echo method, wherein the elastic stiffness constants are derived from the measured ultrasound velocity. On the other hand, the rectangular parallelepiped resonance method or resonant ultrasound spectroscopy, determines the EC from measured resonance spectrum of a specimen. Theoretically, calculations of the internal energy can predict ECs, as ECs are coefficients of the change of the internal energy of the material. The elastic properties of technically important intermetallics: Ni-based Ll2 compounds, titanium aluminides and transition metal disilicides, are discussed.