Abstract

Damage detection in the power industry is always vying for optimized and cheaper techniques. Most components in the energy sector utilize metallic structure, whether it is for power generation, storage, transportation or waste management. Some of these even operate at a high-temperature adding further challenges for its evaluation. Commercial transducers rated for elevated temperatures are limited and expensive. The use of spray-on film transducers for such purposes has been researched while keeping the fabrication simple enough for anyone to create them. Bismuth Titanate (BIT) is an excellent piezoelectric which has a curie temperature of 6700 C and a safe operating level till about 5000 C, considerably higher than PZT. Unlike the preceding sol-gel method, this fabrication process involves a lithium-silicate based inorganic binder and parts water to mix with the Bismuth Titanate powder. This slurry is then sprayed on multiple times onto a metal substrate to form a film greater than 120 ?m in thickness. Electrodes are then attached and the film is poled in an electric field to impart piezoelectricity. With the initial bulk-wave characterization of the film, it was noted that despite a lower piezoelectric coefficient than PZT, the film transducers performed at high-temperatures. Another major advantage is the straightforward fabrication procedure and the ability for these films to cure at a room temperature. Another method to produce these films consisted of all organic materials instead of using the high-temperature inorganic binder. The organic films were also excellent in heat resistance despite having a slightly complicated fabrication procedure compared to the inorganic films. Lithium Niobate (LiN) films are another example of the thin film fabrication procedure.

How to Cite:

Trivedi, Y., Lissenden, C. & Tittmann, B., (2019) “Field deployable spray-on transducers for Lamb wave generation in high-temperature conditions”, Review of Progress in Quantitative Nondestructive Evaluation .