Magnetoelastic Effects: Anisotropic Magnetostriction and Transducer Applications

This lecture covers an introduction to magnetic materials in modern technologies, focusing on magnetoelastic effects. It explains anisotropic magnetostriction, showing how magnets change shape in the magnetic hysteresis and how magnetic and elastic properties vary under stress. The field dependence of Joule magnetostriction is discussed, along with magnetostriction constants for various materials. Stress-induced anisotropy and the Villari effect are also explored. The lecture concludes with transducer applications, highlighting smart magnetostrictive metals like Terfenol and Galfenols used in deep-sea measurements and under-water transducers. Detailed examples of magnetostrictive actuators and the TALON sonar system are presented.