Improved thermal stability of hard magnetic properties in rapidly solidified RE–TM–B alloys
Improved thermal stability of hard magnetic properties in rapidly solidified RE–TM–B alloys
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DOI：
10.1557/jmr.2008.0337
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发表时间：
2008-10
影响因子：
2.7
通讯作者：
Z. W. Liu;R. Ramanujan;H. A. Davies
中科院分区：
文献类型：
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作者：
Z. W. Liu;R. Ramanujan;H. A. Davies
通过熔体纺丝合成了具有增强硬磁性能的快速凝固纳米晶 RE-TM-B（RE = Nd、Pr、Dy，TM = Fe、Co）合金。研究了与成分和微观结构相关的高温磁性能。确定了剩磁 (α) 和矫顽力 (β) 的温度系数。研究了Pr替代Nd、Co替代Fe、Dy替代RE以及晶粒尺寸对居里温度和热稳定性的影响。研究发现 Co 或 Dy 取代对热稳定性具有显着的有益影响。减小晶粒尺寸还可以改善高温行为。在 473 K 的温度下，成分优化的纳米相合金可以获得最大能积 (BH)_max > 100 kJ/m^3。交换耦合纳米复合合金中实现了极低的 α 和 β 系数。还成功制备了 300-400 K 下 α = -0.052%/K 和 β = -0.0365%/K 的粘结纳米复合磁体。
Rapidly solidified nanocrystalline RE–TM–B (RE = Nd, Pr, Dy, TM = Fe, Co) alloys with enhanced hard magnetic properties were synthesized by melt spinning. The composition- and microstructure-dependent elevated temperature magnetic properties were investigated. The temperature coefficients of remanence (α) and coercivity (β) were determined. The effects of Pr substituting Nd, Co substituting Fe, Dy substituting RE, and grain size on the Curie temperature and thermal stability were studied. Co or Dy substitutions were found to have a significant beneficial effect on the thermal stability. Reducing grain size could also improve elevated temperature behavior. Maximum energy product (BH)_max > 100 kJ/m^3 could be obtained in compositionally optimized nanophase alloys at temperature of 473 K. Extremely low coefficients of α and β were realized in exchange coupled nanocomposite alloys. Bonded nanocomposite magnets with α = −0.052%/K and β = −0.0365%/K for 300–400 K were also successfully fabricated.