Cymbal drivers utilizing relaxor-based ferroelectric single crystal materials

The U.S. Naval Research Laboratory (NRL) is currently investigating the performance of flextensional cymbal-based driver elements for use in a number of Navy-based applications, including underwater sound projectors and vibro-acoustic control. The active material in the cymbal driver has traditionally been a piezoelectric ceramic, namely Navy Type VI (PZT-5H). Standard 6.35-mm diameter cymbals driven by this piezoelectric ceramic exhibit a large axial displacement (1.7 μm @ 100 V/mm - 0.1 Hz) but with a large hysteresis. There is great interest in eliminating this displacement hysteresis from the driver performance, especially in active control applications. Cymbals driven by relaxor-based ferroelectric single crystals exhibit markedly higher displacements (2.2 μm @ 100 V/mm - 0.1 Hz) but with no hysteresis. This presentation will compare the displacement characteristics of cymbals driven by a PZT-5H and PZT-4 ceramic to ones utilizing PZN-4.5%PT single crystals as the active material