Non-collinear wave mixing for a bulk wave phase velocity measurement in an isotropic solid

A measurement method is presented to estimate the bulk wave phase velocity in an isotropic solid when longitudinal or shear wave velocity is known. This method is based on the non-collinear plane wave interaction theory and it does not need to estimate the phase time-of-flight and wave propagation path of ultrasonic wave in a specimen. It is necessary to measure incident angles of pump waves for estimation of the longitudinal or shear wave phase velocity. Using the proposed method, the shear wave phase velocity is measured in an aluminum specimen to be 3189 m/s ± 202 m/s and 3174 m/s ± 112 m/s at a level of confidence of 95 % depending on a selected wave mixing method.