Thermo-magnetic characterization and fully coupled finite element modeling of tailored magnetostrictive (Tb 0.3 Dy 0.7 Fe 1.95 ) particulate composites

Giant magnetostrictive rare-earth-alloy-based composites are promising candidates for advanced sensors, actuators, and multifunctional devices yet their applicability restricted at elevated temperatures. In particular, 0–3 type composites enable tailoring of material properties through controlled particle distribution and orientation, making their comprehensive characterization essential for practical applications. In this study, Tb 0.3 Dy 0.7 Fe 1.95 /epoxy composites with particle weight fractions ranging from 15 wt% to 65 wt% were fabricated with both random and aligned particle orientations. The magnetostrictive response of the developed composites was systematically investigated under combined thermal and magnetic fields and compared with predictions from a fully coupled finite element model. The effective properties of the composites were first estimated using micromechanics in COMSOL Multiphysics ® , and subsequently employed in simulations to evaluate their thermo-magneto-mechanical behavior. Magnetization and XRD measurements demonstrated the proper alignment of particles and its anisotropic behavior with aligned directions. A broad range of magnetostriction (40–500 ppm) has been reported for the prepared composites under an applied field of 4000 Oe. Magnetostriction was further accessed across a service temperature range of 25°C–60°C, exhibiting strain from 12 ppm to 115 ppm at 60°C under a low field of merely 2000 Oe, indicating its potential for moderate temperature applications. The predicted simulation results are in good alignment with the measured figures. This integrated experimental–numerical approach provides critical insights into the influence of particle concentration, orientation, and thermal effects on magnetostriction, thereby advancing the design and optimization of magnetostrictive composites for device-level applications.