【作者】 刘兆龙； 胡海云； 范天佑；

【Author】 Liu Zhaolong Hu Haiyun Fan Tianyou School of Science,Beijing Institute of Technology,Beijing 100081

【机构】 北京理工大学理学院；

【摘要】 本文研究了铁磁体内脆性微裂纹在静磁场中的形成过程。采用裂纹的位错滑移合并塞积成核模型,考虑铁磁材料畴壁能和磁势能,给出了磁场中裂纹系统的能量;并根据能量平衡原理,推导出磁场作用下材料的临界载荷和裂纹形成阶段微裂纹的长大速率。发现磁场的作用可以使材料的临界裂纹长度更小,微裂纹的长大速率更低,临界载荷值更大。更多还原

【Abstract】 The formation of cracks in static magnetic field is investigated for ferromagnetic materials.Using the mechanism for nucleation of cleavage cracks due to the coalescence of glide dislocations on intersecting slip planes,the energy of crack system in magnetic field is given and the critical load and the growth speed of micro crack are derived base on the energy balance condition.The effect of magnetic field on the critical load,the growth speed of micro crack and the critical length of micro crack are discussed.Our results show that the length of a micro crack growing in magnetic field can be less than that for a micro crack growing under the action of applied stress only and the growth speed of micro crack can be reduced due to magnetic field.更多还原