Preparation of high performance sintering Nd-Fe-B magnet by optimizing strip cast microstructure of master alloy

被引：0
作者：
机构：
[1] Ningbo Ketian Magnet Co., Ltd, Ningbo Jintian Group
来源：
Xu, F. (xuf@jtgroup.com.cn) | 1600年 / Editorial Office of Chinese Journal of Rare Metals卷 / 37期
关键词：
Binary powder blending technique; Grain boundary phase; Sintering Nd-Fe-B; Strip structure;
D O I：
10.3969/j.issn.0258-7076.2013.06.007
中图分类号：
学科分类号：
摘要：
The high performance sintering Nd-Fe-B magnet with intrinsic coercivity 1027 kA·m-3 and maximum energy product 415 kJ·m-3 was prepared by a binary powder blending technique on the industrialization product line. The magnet had strong corrosion resistance; the mass loss of the magnet was only 2.08 mg·cm-2 after 168 h under the condition of 121°C, 0.27 MPa and 100% relative humidity. The effects of main alloy strip structure on sintering magnet microstructure and magnetic performance were investigated. Owing to the low rare earth concentration of the master alloy, there were a lot of α-Fe phases near the free surface of Nd28.0Fe70Co1.0B1.0 strip cast flakes, subsequently the magnet had much aggregation of Nd-rich phase, the grain boundary was unsmooth, and then the magnet had low density of 7.45 g·cm-3, the coercivity was only 870 kA·m-1. After optimizing the strip cast flakes structure, the α-Fe phases in the strip cast flakes were suppressed and Nd2Fe14B columnar grains of about 3~4 μm were formed along the solidification direction. There was less aggregation of Nd-rich phase in the magnet, the distribution of Nd-rich phase was uniformity and the grain boundary was straight and smooth. At last, the magnet density was enhanced to 7.57 g·cm-3, the coercivity was increased to 1027 kA·m-1.
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页码：889 / 895
页数：6
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