Abstract:

Recent research into PMN (lead magnesium niobate)-based electrostrictive materials have led to compositions with strain rates significantly higher than that of piezoelectric ceramics. The large strain rate makes it ideal for use in high-power SONAR transducers. However, unlike piezoelectric ceramics, the properties of PMN vary nonlinearly with temperature. The highest performance PMN compositions exhibit optimal characteristics at temperatures near 85 (degrees)C. AlliedSignal has solved the engineering challenges of implementing a high-temperature PMN composition in a SONAR transducer and demonstrated the performance at NUWC Lake Seneca test facility. This paper discusses the properties of high-temperature PMN materials and presents the test results of a PMN transducer compared with a similar transducer which utilizes conventional piezoelectric ceramic. The PMN transducer produced roughly 6 dB higher source level than the PZT transducer. Electromechanical coupling and bandwidth of the two transducers was similar.