Replacement of Nd by an intermetallic phase in the intergranular region of Fe‐Nd‐B sintered magnets
Replacement of Nd by an intermetallic phase in the intergranular region of Fe‐Nd‐B sintered magnets
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DOI：
10.1063/1.349940
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发表时间：
1991-11
影响因子：
3.2
通讯作者：
B. Grieb;C. Pithan;E. Henig;G. Petzow
中科院分区：
文献类型：
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作者：
B. Grieb;C. Pithan;E. Henig;G. Petzow
Fe-Nd-B基磁体的显微组织主要由嵌入在主要为Nd加上一些Fe4Nd1.1B4（η）的共晶基体中的Fe 14 Nd 2 B（Φ）晶粒和由杂质稳定的Fe-Nd相组成。向Fe-Nd-B材料中添加Al或Ga导致形成基于Fe、Nd和Al或Ga的完全不同的三元晶间相。通过这些添加物稳定的主相是组成为Fe 70 − xNd 30 Tx的相（δ）（对于T=Al：8≤x≤25;对于T=Ga：3≤x≤8）。在标准磁体组合物中，纯Nd在晶间区域中仍然占主导地位，并且由于对氧气和湿度的高敏感性而导致腐蚀问题。通过基于相关系的知识为母合金选择适当的总成分，可以产生由Φ和几乎没有残留Nd相的晶间Fe-Nd（Al或Ga）相组成的新的显微组织。这种材料的磁参数与传统的Fe-Nd-B材料相当甚至更好。δ相结晶器
The microstructure of Fe‐Nd‐B based magnets consists of mainly Fe14Nd2B (Φ) grains embedded in a eutectic matrix of mainly Nd plus some Fe4Nd1.1B4 (η) and Fe‐Nd phases stabilized by impurities. The addition of Al or Ga to Fe‐Nd‐B material leads to the formation of quite different ternary intergranular phases based on Fe, Nd and Al or Ga. The main phase stabilized by these additions is a phase (δ) with the composition Fe70−xNd30Tx (for T=Al: 8≤x≤25; for T=Ga: 3≤x≤8). In standard magnet compositions the pure Nd is still dominant in the intergranular region and causes corrosion problems due to high sensitivity to oxygen and humidity. By choosing an appropriate gross composition for the master alloy based on the knowledge of the phase relations, a new microstructure can be created consisting of Φ and an intergranular Fe‐Nd (Al or Ga) phase almost without the residual Nd phase. The magnetic parameters of this material are comparable to or even better than those of conventional Fe‐Nd‐B materials. The δ phase cr...