Prestressed Electrodes for Spherical Transducers

The power‐handling capabilities of ceramic piezoelectric transducers in pulsed operation at low duty rate are limited by tensile rupture. Compressive bias has been used to increase the power‐handling capabilities of integral spheres; this mechanical bias has been applied by controlled nickel electroplating over the outer surface, such that the plated coating is under high tensile stress. Units formerly limited to 50 W/cm² can now be operated at 200 W/cm³.