Session: 07-01: NDE for Additive Manufacturing / 03-01: Electromagnetic NDE Techniques

Paper Number: 137507

137507 - The Magnetic Design of High Temperature Electromagnetic Acoustic Transducers 

Abstract: 

The use of Electromagnetic Acoustic Transducers (EMAT’s) is attractive due to their non-contacting transduction, allowing them to be easily installed on engineering assets and work through coatings. Additionally, the non-contacting nature is particularly important on safety critical assets where EMAT installation is considered to be minimally intrusive. Many engineering assets operate at elevated temperatures where there is a risk of a range of thermally activated damage mechanisms, and consequently it is necessary to design EMAT’s that withstand the operating temperatures. Frequently, EMAT's are designed to maximize the bias magnetic field, to achieve compact designs, or to achieve particular targeted ultrasonic modes; but such designs may be vulnerable to reversible and irreversible magnetic losses. In this study the importance of considering the magnetic design to avoid reversible and irreversible magnetic losses associated with high temperature exposure is highlighted. The basic theory and analytical methods are presented, together with the resulting design guidelines. Experiments show that the design of the EMAT can be optimized to avoid losses. Experiments will be conducted on Neodymium and specialist high-temperature magnets will be presented. Other factors that may be beyond the EMAT engineers control such as the operating environment and test medium are also important and given consideration.

Presenting Author: Joseph Corcoran University of Cincinnati

Presenting Author Biography: Joseph Corcoran joined the University of Cincinnati as Associate Professor in 2020. He received his MEng and PhD degrees in Mechanical Engineering from Imperial College, where he maintains an Honorary Lecturer position. His research interests lie in the development of Structural Health Monitoring (SHM) systems and ‘smart’ structural integrity assessments through the Digital Twin concept. His research covers electromagnetic and ultrasonic methods, analytical and experimental techniques and the development of both hardware and software solutions.

Authors:

Nived Suresh University of Cincinnati
Pierce Elliott University of Cincinnati
Joseph Corcoran University of Cincinnati