Failure Analysis of High-Power Piezoelectric Transducers

摘要

Low-frequency projectors for underwater sound are often driven near stress limits because of the conflicting requirements of high power and small size. One common failure mode is ceramic cracking and the associated arcing between high-voltage electrodes. While there are a number of manufacturing defects that can cause premature electric breakdown or premature cracking, a fundamental problem results from the coupling between the electric field and stress in a piezoelectric material. For a transducer operated near resonance, there will be "hot spots" or regions of locally intense stress and electric field that precipitate premature failure. The long-term goals of this project are: (1) to develop a capability to describe such failure modes, (2) to understand the factors that precede failure, and (3) to develop guidelines for failure mitigation.