湿空气中恒磁场导致(Tb,Dy)Fe_2合金的滞后开裂  

DELAYED CRACKING INDUCED BY CONSTANT MAGNETIC FIELD IN HUMID AIR FOR (Tb, Dy)Fe_2 ALLOY

作　　者：钮萼[1] 何健英[1] 乔利杰[1] 褚武扬[1] 于敦波[2] 李扩社[2] 

机构地区：[1]北京科技大学材料物理系,北京100083 [2]北京有色金属研究总院稀土材料国家工程研究中心,北京100088

出　　处：《金属学报》2006年第4期369-373,共5页Acta Metallurgica Sinica

基　　金：国家自然科学基金项目50572006;北京市自然科学基金项目2062012资助

摘　　要：对(Tb,Dy)Fe2超磁致伸缩合金,用微分相衬显微镜原位研究了应力和磁场引起的畴变、卸载压痕裂纹在湿空气中的滞后扩展以及在湿空气中恒磁场引起的滞后畴变及滞后开裂．结果表明,当磁场大于门槛值Hth后就能使压痕裂纹发生瞬时扩展;在湿空气中,残余应力能使(Tb,Dy)Fe2发生滞后扩展,当裂纹止裂后,恒磁场(H<Hth)能使磁畴发生滞后变化,并能使压痕裂纹进一步发生滞后扩展．In situ observation of delayed propagation of unloaded indentation crack in humid air, as well as delayed domain change and delayed cracking induced by constant magnetic field in humid air for （Tb, Dy）Fe2 magnetostrictive alloy have been investigated using differential inference contrast microscope. The results showed that a magnetic field exceeded the threshold field Hth caused instant propagation of indentation crack. In humid air, a residual stress during indenting could cause delayed propagation of unloaded indentation crack, and after the propagation arrested a constant magnetic field below Hth could cause delayed change of domain configuration as well as delayed propagation of indentation crack again.

关 键 词：(Tb Dy)Fe2 畴变 恒磁场 滞后开裂 

分 类 号：TG111.91[金属学及工艺—物理冶金]