Static and Dynamic Magneto-Elastic Sensing Properties of Fe-Al Alloy Powder-Epoxy Composite Patches

By combining the two types of magnetoelastic and magnetochromatic materials in an epoxy, we can make a hybrid system that exhibits optical response due to elastic strain. It could be used structural health monitoring, for real-time monitoring crack propagation or general evaluation condition structure, both visualized by change color. In this study, magnetostrictive polymer composites (MPCs) with Fe81Al19 (Alfenol) alloy particles are evaluated determine magneto-elastic properties composite patches attached surface, prior understanding full magneto–elasto–optical interactions. To measure static performance, tension apparatus within solenoid was fabricated apply uniform strain MPC patch on aluminum dog-bone substrate. demonstrated that, epoxies modulus higher than ~0.1 GPa, tensile strain/stress applied improved coupling, resulting increased permeability values, at least up strains 0.1%. Composites were spherical flake-shaped powders, powders exhibiting better magnetic responses those morphology. Alfenol MPCs also measured dynamically ultrasonic frequencies, comparable dynamic sensing performance Galfenol 120 kHz using guided wave techniques.