Nd_9Fe_(85.5-x)Co_xB_(5.5)快淬薄带晶化动力学研究  

Crystallization kinetics of melt-spun Nd_9Fe_(85.5-x)Co_xB_(5.5) amorphous ribbons

作　　者：邓福涛[1] 刘新才[1] 潘晶[1] 李明[1,2] 姜小丽[1] 鲁贻虎[1,2] 

机构地区：[1]宁波大学材料科学与化学工程学院,宁波市新型功能材料及其制备科学重点实验室,浙江宁波315211 [2]宁波大学理学院,浙江宁波315211

出　　处：《功能材料》2014年第3期92-95,100,共5页Journal of Functional Materials

基　　金：国家自然科学基金资助项目(51174121;51274125);浙江省重大科技专项资助项目(2008C11086-1);浙江省重点科技创新团队资助项目(2010R50016-8);宁波大学学科资助项目(xkl09075)

摘　　要：采用真空再充Ar保护的DSC 测量了Nd9Fe85.5-xCoxB5.5（x =3%,5%（原子分数））非晶薄带的升温曲线,计算了两种非晶薄带的晶化激活能E、频率因子Z、反应速率常数K 、Avrami指数n.实验证实了Co从3%（原子分数）增大到5%（原子分数）时晶化过程从一步改变为两步晶化;计算结果表明晶化起始温度Tx 及晶化峰值温度Tp 的晶化激活能、晶化反应速率常数均随Co的增加而增大,其主要原因是增大的频率因子起了关键作用;分析计算结果认为Nd9Fe82.5Co3B5.5在升温速度10K/min时局域Avrami指数n 随着晶化体积分数x 的增加先急剧降低而后缓慢降低、90%之后又有所升高,表明晶化形核在x 〈12%以三维形核方式为主,在x 为12%～36%时晶化以二维形核方式为主,之后直到晶化结束以-维形核方式为主.The heating curves of Nd9 Fe85 .5-x Cox B5 .5 （x=3%,5at%）amorphous alloy ribbons were measured by DSC protected by filling argon after vacuuming.The crystallization activation energy E,frequency factor Z,re-action rate constant K and Avrami exponent n of the two kinds of amorphous alloy ribbons were calculated ac-cording to the DSC curves.It was confirmed that the crystallization process changes from one step to two-steps with Co content increasing from 3% to 5at%.And the higher Co content in the alloy,the higher crystallization activation energy E and crystallization reaction rate constant K of both the initial crystallization temperature Tx and the peak one Tp.This was the reason that the increase of frequency factor Z playes a key role.At the heat-ing speed 10K/min,the local Avrami exponent n of Nd9 Fe82 .5 Co3 B5 .5 decreases sharply at first and then slow down with the increase of crystallization volume fraction x ,but it rises again when x was more than 90%.It demonstrates that when x was less than 12%,the crystallization nucleation mainly in the three-dimensional nu-cleation mode,and it changes into the two-dimensional nucleation one when x was 12%-36%,after 36% it does in the one-dimensional nucleation one.

关 键 词：晶化动力学 频率因子 晶化激活能 AvraGmi指数n 纳米双相永磁材料 

分 类 号：TB332[一般工业技术—材料科学与工程]