Composite Terfenol-D Transducers for Underwater Arrays
Small Business Information
161 First St, Cambridge, MA, 01242
Michael J. Gerver, Ph.d.
AbstractOriented composites of PZT and polymer can have properties superior to ordinary PZT as drivers for sonar transducers and hydrophones because they have a lower Poisson ratio, and a lower dielectric constant. Terfenol-D is superior to ordinary PZT because it has larger maximum strains and higher energy density, and is not subject to fatigue or depoling. For these reasons, composite Terfenol-D should be superior to both composite PZT and ordinary Terfenol-D. This is especially true at high frequencies, since the brittleness of ordinary Terfenol-D makes laminating it expensive and does not allow very thin laminations. SatCon proposes to investigate the hydrostatic magnetostrictie properities of an improved composite Terfenol-D recently developed by Prof. G. Carman's group at UCLA. It is the hydrostatic properties that are relevant for underwater sonar transducers with dimensions that are small compared to a wavelength, as would be true of a small transducer used in an array. In collaboration with the UCLA group, we will develop Terfenol composites that are optimized for sonar and hydrophone use (e.g., reducing the Poisson ration). A small composite Terfenol-D transducer, operating in the 1kHz to 20kHz range, will be designed and built in Phase I, and a full array will be built and demonstrated in Phase II.
* information listed above is at the time of submission.