Revised Grain‐Scattering Formulas and Tables

The current theory of Rayleigh and stochastic phase scattering of ultrasound in polycrystalline materials is reviewed and compared with (1) former theory and (2) experiment. It is found that, when the grain size is evaluated properly, the current theory accounts rather well for the scattering component of the ultrasonic attenuation of polycrystalline materials. A tabulation is made of the coefficients of attenuation caused by scattering for various materials. These coefficients multiplied by a factor involving the grain size and a factor involving a power of the ultrasonic frequency give the attenuation.