ELASTIC-CONSTANTS OF SINGLE-CRYSTAL GAMMA-TIAL

The six independent second-order elastic stiffness coefficients of a T i44Al56 Single crystal (L1(0) structure) have been measured at room te mperature for the first time using a resonant ultrasonic spectroscopy (RUS) technique. These data were used to calculate the orientation dep endence of Young's modulus and the shear modulus. Young's modulus is f ound to reach a maximum near a [111] direction, close to the normal to the most densely packed planes. The elastic moduli and Poisson's rati o for polycrystalline materials, calculated by the averaging scheme pr oposed by Hill, are in good agreement with experimental data and theor etical calculations.