Texture of polycrystalline metals characterized by ultrasonic velocity measurements

An ultrasonic method is presented for the nondestructive evaluation of the rolling texture in polycrystalline aggregate of cubic metals. Use is made of the elastic anisotropy measured by the propagation velocities of Rayleigh surface waves and surface skimming SH waves in the rolling plane. These velocity anisotropies permit the evaluation of the lowest three coefficients in the series expansion of the orientation distribution function and then enable the calculation of ‘‘ultrasonic pole figures’’ for the surface texture. The correspondence with the conventional x-ray pole figures is comparatively good for the aluminum alloy tested, showing that the ultrasonic pole figures properly approximate the conventional x-ray pole figures. The limitation and application are discussed.