Nd-Fe-B烧结磁体的磁化行为  

MAGNETIZATION BEHAVIOR IN SINTERED Nd-Fe-B MAGNETS

作　　者：李东[1] K.J.Strnat H.F.Mildrum 

机构地区：[1]钢铁研究总院 [2]美国戴登大学

出　　处：《中国稀土学报》1989年第1期28-33,共6页Journal of the Chinese Society of Rare Earths

摘　　要：研究了热退磁态和磁场退磁态Nd-Fe-B和Nd-Dy-Fe-B烧结磁体室温至150℃不同磁化场的磁化曲线、退磁曲线和磁滞回线。室温下磁场退磁态磁化曲线和内禀矫顽力_MH_C随磁化场H_M的变化曲线在磁化场接近样品最大内禀矫顽力绝对值时出现台阶,当温度升至100～150℃或样品在居里温发以上热退磁后,磁化曲线的形状由阶梯型变成陡峭型,而且_MH_C—H_M曲线的台阶移到低磁化场。膝点矫顽力H_K随H_M的快速升高出现在_MH_C随H_M的快速升高之后。表明Nd-Fe-B烧结磁体的磁硬化主要被畴壁钉扎所控制。Magnetization and demagnetization curves and hysteresis loops applied different magnetizing fields in sintered Nd-Fe-B and Nd-Dy-Fe-B magnets from thermally demagnetized and dc field-demagnetized states were investigated at temperatures of up to 150℃. The dc field-demagnetized state of magnets was obtained by a recoil through the origin after saturation magnetization with 100kOe pulsed field and de field of 30 kOe and demagnetization with de field at room temperature. The remagnetization curves along easy axis from de field-demagnetized state show a flat part before steeply rising near the field equalled absolute value of the maximum intrinsic coercivity. The curves of coercive forces _MH_c versus remagnetizing fields H_m from dc field-demagnetized state at room temperature show a step around magnetizing field as absolute value of the maximum intrinsic coercivity. The steps of _MH_c-H_m curves shifte to lower remagnetizing fields and the shapes of magnetization curves changed from step-type to precipitous-type when temperature went up to 100℃ to 150℃ or after the specimen was thermally demagnetized at a temperature higher than the Curie temperature. The steep rise of knee coercivity with increasing magnetizing field is behind that of _MH_c.The minor loops during remagnetizing from dc field-demagnetied state and during demagnetization after saturation are almost reversibly traced with no significant loop area.Note that the magnetic hardening in sintered Nd-Fe-B based magnets is controlled by pinning of domain walls.

关 键 词：ND-FE-B 烧结磁体 磁体 磁性材料 

分 类 号：TM271[一般工业技术—材料科学与工程]