LAMB WAVE-PROPAGATION IN MAGNETOSTRICTIVE POLYCRYSTALLINE FERRITE PLATES

The launching and propagation of Lamb waves in magnetostrictive polycr ystalline ferrite plates was studied. The influence of a magnetic over lay situated parallel to the surface of the plate in the vicinity of t he meander-type transducer on the efficiency of the transducer was inv estigated. The results obtained show that Lamb wave velocities are mor e sensitive to magnetic fields than Rayleigh wave velocity, and that t he use of a magnetic overlay essentially improves the efficiency of th e meander type transducer.