研究了电磁干扰、振动和温度等环境因素对NdFeB永磁性能的影响。研究结果表明:(1)场强或频率越高,失效越大,而交变磁场比稳恒磁场更为严重;(2)交变场下因涡流的"趋肤"效应,导致永磁出现不可逆的热退磁现象,当外场为30kA/m、500Hz干扰时,其失效瞬间即超过15%;(3)振动和高温的共同作用干扰,使得退磁失效情况加剧。
The effects of electromagnetic disturbance, vibrating and temperature on the permanent magnetic properties were investigated. The results show that (1) the magnetic properties decrease as external magnetic field or frequency increase, and the magnetic loss gets more in alternating magnetic field; (2) The irreversible thermal demagnetization of the permanent magnets would happened, due to skin effect of eddy current in alternating magnetic field. Demagnetization would be raised rapidly over 15% when being in 30kA/m,500Hz magnetic field; (3) Demagnetization raised larger as magnets were affected by both vibrating and high temperature.