摘要
依据法拉第电磁感应定律和铁磁性物质在磁化-退磁过程中的能量差异,阐明了铁磁性物体在地磁场中的摆动、振动和周期性往复平动都会引起该物体的自发磁化。虽然每次磁化-退磁过程之后物体上的剩磁增量非常微小,但随着循环次数的增加该物体最终必然被强烈地自发磁化。从而推知:地磁场的矢量特性和纬度效应对金属磁记忆检测与诊断技术适用性和可靠性的影响都不大。
According to Faraday law on electromagnetic induction and the difference of the magnetic energy of ferromagnetic materials in their magnetization and demagnetization, it is clarified that the swing, vibration and periodic translational reciprocation of any object made of ferromagnetic material in geomagnetic field must cause spontaneous magnetization of the object itself. Although the increment of the residual magnetism on the object after every cycle of magnetization-demagnetization process is very small, with the increase of the cycle index the object must be finally magnetized intensely and spontaneously. Thereby it can be deduced that the vector character and latitude effect of the geomagnetic field exert little influence upon the applicability and reliability of metal magnetic memory testing and diagnostic technique.
出处
《无损检测》
北大核心
2005年第12期626-627,654,共3页
Nondestructive Testing
基金
国家自然科学基金资助项目(50371045)
关键词
铁磁性物体
地磁场
自发磁化
Ferromagnetic object
Geomagnetic field
Spontaneous magnetization