A Novel Double-Mode Pulsed EMAT for High-Temperature Elastic Constant Measurement

The mechanical properties of nonferromagnetic metallic materials at high temperatures can be partially characterized by measuring their elastic constants. Electromagnetic acoustic transducers (EMATs) are well-suited for this purpose in high-temperature environments. However, existing high-temperature EMATs face challenges in separating ultrasonic bulk wave modes, resulting in mixed shear and longitudinal waves in echo signals, and reducing elastic constant measurement accuracy. In this work, a high-temperature double-mode pulsed electromagnet EMAT (DM-PE-EMAT) was developed for elastic constant measurements, which separately excited pure shear or longitudinal bulk waves. An experiment was conducted to measure elastic constants at high temperatures. The results showed that the fabricated EMAT could select the desired mode of the excited ultrasonic bulk waves, and the measured elastic constants were consistent with the reference data. This study serves as proof of concept for measuring high-temperature elastic properties in nonferromagnetic metals, providing a foundation for future investigations into other material systems.