A new method for the measurement of ultrasonic absorption in polychristalline materials

A method is presented which allows the direct measurement of the ultrasonic absorption coefficient in polycrystalline materials at frequencies in the lower MHz-range. Based on the measurement of ultrasonic reverberation, the method is restricted to relatively small-sized samples, and to materials that exhibit sufficient grain scattering. Examples of application are demonstrated showing the influence of deformation, heat treatment and magnetic fields on the ultrasonic absorption. Results are discussed in terms of dislocations, respectively. (IZFP)