Sintering behaviour of NdFeB magnets
Sintering behaviour of NdFeB magnets
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DOI：
10.1109/20.42429
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发表时间：
1989-09
影响因子：
2.1
通讯作者：
P. Mcguiness;A. Williams;I. R. Harris;E. Rozendaal;J. Ormerod
中科院分区：
文献类型：
--
作者：
P. Mcguiness;A. Williams;I. R. Harris;E. Rozendaal;J. Ormerod
用高温真空膨胀仪研究了NdFeB磁体在烧结过程中的尺寸变化。这些测量是在用传统粉末冶金方法生产的样品和使用氢爆(HD)作为预压技术生产的压坯上进行的。在给定的温度下，HD压坯的收缩量更大，在氢被脱附的温度下观察到明显的收缩。对具有一系列取向场的烧结体进行的收缩测量表明，压坯的各向异性收缩，沿a轴方向增长。在烧结实验中，将NdFeB磁体以不同的速度冷却到室温，然后进行烧结后热处理。实验结果表明，随着冷却速度的增加，内禀矫顽力呈线性下降。然而，当样品在650℃下退火1h时，所有的矫直磁力值都达到了相同的水平，或多或少抵消了先前冷却速度的影响。>；
The dimensional changes that occur during the sintering of NdFeB magnets were investigated using a high-temperature vacuum dilatometer. These measurements were made on samples produced by the conventional powder metallurgical method and on compacts produced using hydrogen decrepitation (HD) as a premilling technique. The amount of shrinkage at a given temperature was found to be greater for the HD compact, with pronounced contractions being observed at the temperatures where hydrogen is desorbed. Shrinkage measurements, carried out on sintered compacts produced with a range of alignment fields, revealed anisotropic shrinkage of the compact, with the increased growth being along the a-axis direction. In sintering experiments NdFeB magnets were cooled at different rates to room temperature and subsequently given a postsintering heat treatment. The results of the experiments showed that the intrinsic coercivity decreases linearly with increasing cooling rate. However, when the samples were annealed for 1 h at 650 degrees C all coercivity values came up to the same level, more or less nullifying the influence of the previous cooling rate. >