Elastic anisotropy of materials containing columnar crystals was experimentally studied. Equations were obtained, which evaluate the elastic stiffnesses of transversely anisotropic materials from the values of technical constants: Young's modulus Ez, and Poisson's ratios νxz and νyz. These equations were applied to the calculation of elastic stiffnesses of Al-2wt.% Cu alloys containing columnar crystals; the values calculated almost agreed with those obtained from its ultrasonic velocities. The elastic constants determined from the tensile testing, however, were more anisotropic than those from the ultrasonic testing. This discrepancy was explained by the difference in material deformation between two experimental methods. The elastic constants of the solutionized and aged alloys were also obtained to confirm the effect of heat treatments on elastic properties. It was found that the constants were influenced by structures in materials, especially by the second phase such as the eutectic phase or precipitate.
