Development and performance evaluation of a high-temperature electromagnetic acoustic transducer for monitoring metal processing

An electromagnetic acoustic transducer (EMAT) design using an air-cored solenoid coil as a pulsed electromagnet is proposed for the high-temperature non-contact monitoring of metal processing, and the operation of a prototype device is confirmed at temperatures ranging from room temperature to 700 degrees C. The coil generates a biasing magnetic field that allows the device to overcome the Curie temperature limitations of conventional EMATs. Pulse-echo measurements on carbon steel are made at high temperatures, and the superposition of the nth compression method is used as a signal processing technique to confirm that the shear wave velocity decreases with increasing temperature, and it is verified that the EMAT can operate at high temperature.