Production of Rare Earth-Fe Bonded Magnet Powders with High Remanence Utilizing Gas Reaction

利用气体反应生产高剩磁稀土铁粘结磁粉

基本信息

批准号：
10450252
负责人：
SUGIMOTO Satoshi
金额：
$ 4.1万
依托单位：
TOHOKU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10450252/
关键词：
HDDR 3:29 phase permanent magnets disproportionation TbCuィイD27ィエD2 phase

项目摘要

Purpose : Remanence enhanced magnets made from a 2 phase nanostructure of hard and soft magnetic phases, can be prepared by either melt spinning or by mechanical alloying. Our previous work has shown that a 2 phase mixture can also be obtained by the Hydrogenation Disproportionation Desorption Recombination (HDDR) processing of SmィイD23ィエD2(Fe,V)ィイD229ィエD2 into TbCuィイD27ィエD2 type and αFe(V) phases, which exhibits coercivities of about 0.6 MAmィイD1-1ィエD1 (7 kOe) after nitriding. However, the grain size of HDDR processed materials (〜300 nm) is typically an order of magnitude larger than that necessary for remanence enhancement to occur : the soft grains should ideally be 10 - 20 nm. The addition of Co has been shown to be effective in reducing the recombination temperature and grain size of HDDR treated samples. Therefore, the aim of this work was to investigate the effect of Co on the disproportionation and recombination kinetics of SmィイD23ィエD2(Fe,V)ィイD229ィエD2, and to attempt to reduce th … More e grain size of the ィイD2aィエD2Fe(Co,V)/TbCuィイD27ィエD2 type phase mixture.Experimental Procedure : Alloys of SmィイD29.4ィエD2FeィイD284.6-XィエD2CoxVィイD26.0ィエD2 (X = 0, 10, 20 and 30), were induction melted from high purity elements, under an Ar atmosphere, and then homogenized at 1150℃ for 20 hours. X-ray diffraction (XRD) analysis showed that the alloys were near single phase SmィイD23ィエD2(Fe, Co, V)ィイD229ィエD2 with a small amount of αFe(Co, V). The homogenized allows were ground into powders, sieved to a particle size less than 63μm, and pressed into green compacts. Samples were obtained at different stages of the disproportionation reaction, by heating under hydrogen to temperatures between 620 - 700℃, and then after 1 hour, cooling rapidly in hydrogen. HDDR samples were obtained by heating the disproportionated samples under vacuum to temperatures between 590 - 750℃ ; and then after 10 min - 12 hours, cooling rapidly under vacuum. Some of the HDDR samples were then nitrided at 560℃ for 4 hours ィイD23)ィエD2, then ground into powder, which was mixed with molten paraffin that solidified within a magnetic field of 1.0 MAィイD2m-1ィエD2 (12 kOe). The magnetic properties were measured using a vibrating sample magnetometer (VSM). Samples for transmission electron microscopy (TEM) were thinned by ion milling.Results: With the addition of cobalt, the disproportionation temperature of the alloys SmィイD29.4ィエD2FeィイD284.6-XィエD2CoxVィイD26.0ィエD2 (X = 0, 10, 20 and 30) increased, and the recombination temperature decreased. This shows that cobalt stabilizes the SmィイD23ィエD2(Fe, Co, V)ィイD229ィエD2 phase with respect to disproportionation in hydrogen, and increases the rate of the recombination into αFe(Co, V) and TbCuィイD27ィエD2 type phases. With TEM【approximately equal】5 nm diameter rods were observed, which are believed to be SmHs. Grain about 50 - 100 nm in size were found in a 30% Co sample recombined at 630℃ for 1 hour. In addition to αFe(Co, V) and TbCuィイD27ィエD2 type phases, XRD also showed the presence of a yet unidentified phase that forms at high Co contents and low temperature, which appeared to have an adverse effect on the magnetic properties, after nitriding. Less

目的：由硬磁相和软磁相的两相纳米结构制成的剩磁增强磁体可以通过熔体纺丝或机械合金化来制备。我们之前的工作表明，也可以通过氢化歧化解吸复合来制备两相混合物。 (HDDR) 将 SmD23D2(Fe,V)D229D2 加工成 TbCuD27D2 型αFe(V) 相，氮化后表现出约 0.6 MAmidD1-1D1 (7 kOe) 的矫顽力。然而，HDDR 处理材料的晶粒尺寸 (〜300 nm) 通常比剩磁增强所需的晶粒尺寸大一个数量级。发生：软晶粒的理想尺寸应为 10 - 20 nm。 Co 的添加已被证明可有效降低复合温度和晶粒尺寸。因此，这项工作的目的是研究 Co 对 SmD23D2(Fe,V)D229D2 歧化和复合动力学的影响，并尝试减小 D2aD2Fe(Co,V) 的晶粒尺寸。 )/TbCuD27D2 型相混合物。实验程序：合金SmiD29.4D2FeD284.6-XD2CoxVD26.0D2（X = 0、10、20和30）是由高纯元素在Ar气氛下感应熔炼而成，然后在1150℃下均质化20小时（X射线衍射）。）分析表明合金接近单相将含有少量αFe(Co,V)的SmiD23D2(Fe,Co,V)D229D2磨成粉末，过筛至粒径小于63μm，并压制成不同阶段的压坯。歧化反应时，在氢气下加热至620-700℃，然后1小时后，在将歧化后的样品在真空下加热至590-750℃，然后在10分钟-12小时后，将部分HDDR样品在560℃下氮化4小时，得到HDDR样品。）D2，然后研磨成粉末，与熔融石蜡混合在1.0磁场内固化MA-D2m-1-D2 (12 kOe) 使用振动样品磁力计 (VSM) 测量用于透射电子显微镜 (TEM) 的样品，通过离子铣削进行减薄。结果：随着钴的添加，歧化发生了。合金温度SmiD29.4D2FeD284.6-XD2CoxVD26.0D2 (X = 0、10、20 和 30) 增加，复合温度降低，这表明钴稳定了 SmiD23D2(Fe, Co, V)D229D2 相的歧化。氢，并增加了重组为 αFe(Co, V) 和 TbCuD27 型相的速率，用 TEM 观察到【约等于】5 nm 直径的棒，其被认为是尺寸约为 50 - 100 nm 的 SmHs。在 630℃ 1 小时复合的 30% Co 样品中发现除 αFe(Co, V) 和 αFe(Co, V) 外。 TbCuiD27iD2 型相，XRD 还显示存在一种尚未识别的相，该相在高 Co 含量和低温下形成，这似乎对氮化后的磁性能产生不利影响。