Micromagnetic simulation of Nd-Fe-B demagnetization behavior in complex environments

Abstract

With the continuous expansion of the application range of Nd-Fe-B permanent magnetic materials, it becomes increasingly necessary to understand their magnetic performance under different working conditions. Currently, there is limited research on the magnetization characteristics of Nd-Fe-B in complex environments. In this study, a theoretical model considering demagnetizing field, thermal effects, and force-magnetic coupling was established to investigate the demagnetization behavior of Nd-Fe-B under the combined influence of temperature, pressure, and magnetic field. To address the high cost and implementation difficulties associated with demagnetization experiments in complex environments, as well as the limitations of general hysteresis models in terms of research scale, a micromagnetic numerical simulation method incorporating the theoretical model was adopted. The simulation was performed using COMSOL Multiphysics, which allows for multi-physics field coupling. The demagnetization behavior of Nd-Fe-B in complex environments was calculated. The demagnetization curves of Nd-Fe-B under different combinations of temperature, pressure, and magnetic field were obtained. From the perspective of magnetic moment motion, the demagnetization mechanism of Nd-Fe-B was analyzed. Furthermore, the variations in coercivity, Curie temperature, and critical demagnetizing pressure of Nd-Fe-B in complex environments were summarized. These findings provide theoretical guidance for the application of Nd-Fe-B permanent magnetic materials in complex working environments.