Analysis of magnet behaviors within high frequency field and high temperature using micromagnetic simulator

Bonded magnets are some of the most industrially important permanent magnets. They enables to complex shapes to be achieved and are stronger than other magnets. NdFeB anisotropic bonded magnets are used in motors of automobiles and magnetic hard disks and sensors utilized in a wide variety of products [1]. In the future, bonded magnets will be needed for motors of hybrid vehicles (HV) and electric vehicles (EV), which are anticipated to become smaller and have higher rotational speed. However, we are concerned that a high frequency field of 10 kHz and high temperature will demagnetize the magnets. This demagnetization will also depend on a static DC-field about 3–4 kOe. We call this demagnetization phenomena ‘magnetic fatigue’. In this study, magnet behaviors within the high frequency field and at high temperature were simulated using a micromagnetic simulator.