PZT materials withstand extreme deep sea pressures

The tests involve a variety of ceramic formulations typically used in underwater applications, including both soft and hard PZT types. The objective was to better understand the behaviour of the materials and any changes in their electrical properties after tens or hundreds of exposures to very high pressures.

A pressure of 27,000psi was applied to each ceramic type, equivalent to a depth of 18,500m underwater. This is beyond the maximum known deepest point in the ocean, the Mariana Trench, which at a depth of 10,994m (±40m) exerts a pressure of 15,750psi, more than 1,000 times the standard atmospheric pressure at sea level.

Results showed that Morgan’s PZT5A1 soft and PZT401 hard formulations suffered no signs of depolarisation at this pressure. Depolarisation has always been a concern for transducer design engineers, in the selection process of ceramic materials for deep sea applications and the traditional preference has been to use a hard based ceramic material. However, these results confirm that a soft product can now be specified delivering equal performance.

Paul Turnbull, Morgan Advanced Materials explained: “The ability to withstand multiple pressure cycles is key to guaranteeing the long-performance of PZT materials for use in deep water applications. Our tests, comfortably exceeding any pressures materials are likely to face, saw our materials excel in extreme conditions, providing further reassurance for specifiers and customers of our ability to meet the most demanding performance parameters.”