Synergetic crystallization in a Nd2Fe14B/α-Fe nanocomposite under electron beam exposure conditions.
Synergetic crystallization in a Nd2Fe14B/α-Fe nanocomposite under electron beam exposure conditions.
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DOI：
10.1039/c6nr06884g
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发表时间：
2016-10
期刊：
影响因子：
6.7
通讯作者：
Haidong Tian;Yinfeng Zhang;Jingzhi Han;Zhuang Xu;Xiaodong Zhang;Shunquan Liu;Changsheng Wang
中科院分区：
文献类型：
--
作者：
Haidong Tian;Yinfeng Zhang;Jingzhi Han;Zhuang Xu;Xiaodong Zhang;Shunquan Liu;Changsheng Wang
用电子束辐照法制备了Nd2Fe14B/α-Fe纳米复合磁体，其热处理时间大大缩短了0.1%S，这是目前为止最有效的方法，因为它具有极高的加热速度和快速的加热过程。通过对朗道模型和朗之万动力学模拟的介绍，阐述了快速热过程对结晶的影响。研究了在常规退火条件下，Nd2Fe14B相之前的α-Fe相到电子束条件下的协同晶化顺序的变化。协同晶化导致α-Fe相和Nd2Fe14B相之间的相互作用更加强烈，从而在我们的添加范围内随着Fe含量的增加而细化组织。α-Fe相的均匀分布、显微组织和分布的变化有助于磁性能的改善。与常规的炉退火相比，样品在电子束曝光条件下的磁性能得到了改善。Nd10Fe83.3B6.2Nb0.2Ga0.3合金的矫顽力从4.56 kOe提高到6.73 kOe，剩磁比从0.75增加到0.79，磁滞回线具有良好的正方形。
Nd2Fe14B/α-Fe nanocomposite magnets are prepared through electron beam exposure with a greatly reduced annealing time of 0.1 s. This is by far the most effective approach due to the effect of an extremely high heating rate featuring a rapid thermal process. The impact that the rapid thermal process has on crystallization is expounded by the introduction of the Landau model and Langevin dynamical simulations. The change of crystallization sequence from the α-Fe phase preceding the Nd2Fe14B phase under conventional annealing conditions, to synergetic crystallization under electron beam conditions is investigated. Synergetic crystallization results in more intense interaction between the α-Fe phase and the Nd2Fe14B phase in order to refine the microstructure as the fraction of Fe increases within our addition range. Improved uniformity, and shifts in the microstructure and distribution of the α-Fe phase contribute to the improvement of the magnetic properties. Compared with conventional furnace annealing ones, the magnetic properties of samples under electron beam exposure conditions are improved. For the Nd10Fe83.3B6.2Nb0.2Ga0.3 alloy, coercivity is enhanced from 4.56 kOe to 6.73 kOe, remanence ratio increases from 0.75 to 0.79, and a superior squareness of the hysteresis loop is achieved.