Rfe10.5V1.5Nx化合物的结构和内禀磁性研究

系统地研究了Rfe_10.5V_1.5N_x（Ｒ＝Ｙ，Ｃｅ，Ｎｄ，Ｓｍ，Ｇｄ，Ｔｂ，Ｄｙ，Ｈｏ，Ｅｒ）化合物的结构和内禀磁性，并与相应的Rfe_10.5V_1.5N_x化合物进行了比较。同Rfe_10.5V_1.5N_x化会物相比，由于ｖ含量低，Rfe_10.5V_1.5N_{x关键词：}     

机械合金化Nd(Fe, Mo)12Nx的结构与磁性能

用机械合金化方法制备了ＮｄＦｅＭｏ微晶，通过７５０～９５０℃的晶化及随后的氮化处理，生成了ＴｈＭｎ１２型Ｎｄ（Ｆｅ，Ｍｏ）１２Ｎｘ化合物。通过Ｘ射线、透射电镜和磁测量研究了化合物的结构、形成条件和磁性能，并与其他ＴｈＭｎ１２型氮化物比较，结果表明：Ｎｄ（Ｆｅ，Ｍｏ）１２Ｎｘ成相条件好、磁性能高，是一种优良的永磁材料化合物。     

烧结Sm2Co17型永磁材料的力学性能及断裂行为的各向异性

对从同一磁体上切取的取向方向不同的三组烧结Sm2Co17试样的抗弯强度进行测定,对其抗弯断口进行宏观观察和扫描电镜观察.对烧结Sm2Co17型永磁材料的力学性能和断裂行为的各向异性进行了研究.研究结果表明:烧结Sm2Co17型永磁材料的抗弯强度和断裂行为具有明显的各向异性,烧结Sm2Co17型永磁材料断裂的微观机制为解理断裂,材料易于沿密排面(0001)面或沿与密排面的夹角大约为60°的晶面解理断裂 关键词： Sm2Co17型永磁 抗弯强度 解理断裂 各向异性     

烧结SmCo永磁材料的断裂

对烧结Sm₂Co₁₇型永磁材料的抗弯强度和断裂韧性KIC进行测定, 对其抗弯断口进行扫描电子显微镜观察及能谱分析, 研究了烧结Sm₂Co₁₇型永磁材料的断裂行为及其微观机制. 研究结果表明：烧结Sm2Co17型永磁材料的断裂为解理断裂. 断面上存在富Sm的氧化物夹杂, 富Sm夹杂物的存在有利于减低烧结Sm₂Co₁₇型永磁材料的解理脆性, 并由此提出改善烧结Sm₂Co₁₇型永磁材料强韧性的途径.     

CRYSTALLOGRAPHIC STRUCTURE AND INTRINSIC MAGENTIC PROPERTIES OF R2Fe14BNx

We found that the nitrogen atoms can enter into the R₂Fe₁₄B structure by a proper heat treatment in nitrogen atmosphere. The crystallographic structure and magnetic properties of R₂Fe₁₄BN_x, R =Nd and Y, have been investigated by using X-ray and neutron diffraction techniques as well as magnetic measurements. The neutron diffrac-tion data show that the nitrogen atoms occupy the 4f interstices. The interstitial nitrogen atoms were found to have an effect of enhancing Curie temerature, whereas, decreasing saturation magnetization and magneto-crystalline anisotropy. The rela-tionship of the crystal structure and the intrinsic magnetic properties of this crystal is discussed.     

CRYSTALLOGRAPHIC STRUCTURE AND INTRINSIC MAGENTIC PROPERTIES OF R2Fe14BNx

We found that the nitrogen atoms can enter into the R₂Fe₁₄B structure by a proper heat treatment in nitrogen atmosphere. The crystallographic structure and magnetic properties of R₂Fe₁₄BN_x, R =Nd and Y, have been investigated by using X-ray and neutron diffraction techniques as well as magnetic measurements. The neutron diffrac-tion data show that the nitrogen atoms occupy the 4f interstices. The interstitial nitrogen atoms were found to have an effect of enhancing Curie temerature, whereas, decreasing saturation magnetization and magneto-crystalline anisotropy. The rela-tionship of the crystal structure and the intrinsic magnetic properties of this crystal is discussed.     

Fracture in sintered Sm−Co permanent magnetic materials

The bending strength and fracture toughness of sintered Sm-Co permanent magnetic materials are measured. A scanning electron microscope equipped with an energy dispersive X-ray analysis system is employed to investigate the bending fractography. The fracture behavior and micromechanism are discussed. The fracture behavior of sintered Sm-Co permanent magnetic materials exhibits cleavage fracture. Some Sm-rich impurities are found in fracture plane, suggesting that the Sm-rich impurities help reduce the cleavage brittleness of sintered Sm-Co permanent magnetic materials. The possible methods for improving the strength and toughness are also proposed.     

烧结(Pr,Nd,Dy)32.2Co13Cu0.4FebalB0.98磁体磁性能和微观组织的研究

以烧结Nd-Fe-B磁体为基,复合添加了Cu,Co和重稀土Dy,成功制备了具有优良温度稳定性的磁体,磁体最高使用温度T_w≈210℃,剩磁温度系数α=-0.053%·℃^-1。研究发现,所制备磁体中存在着大量块状富稀土晶界相,而严重缺乏薄层富稀土晶界相,即使经过二级回火,薄层富稀土晶界相数量也没有明显增加。在块状富稀土晶界相中有贫Co相和富Co相同时存在的现象。TEM观察发现在富Co相中有RE₂(Fe,Co)₁₇相的存在,这不利于矫顽力的提升。研究表明：晶界处Cu和Co是对立分布的,经过合理的回火工艺后,Cu在晶界的分布更为均匀,Co则主要分布在晶界角落。此外,在一级回火水淬态磁体中的富Co相区域内,发现了RE(Fe,Co)₂ Laves相。     

复相Nd4.5Fe76.3Ga0.3Co1.0B18合金的结构与磁性

利用快淬法制备了Nd_4.5Fe_76.3Ga_0.3Co_1.0B₁₈非晶合金,晶化处理后获得主相为Fe₃B与Nd₂Fe₁₄B的纳米晶永磁材料.采用X射线衍射、透射电子显微镜及磁测量手段分析研究了材料的微观结构与磁性能,并通过测量磁体的δM曲线,研究了晶粒间的交换耦合作用及其与微观结构、磁性能的关系. 关键词：     

烧结Nd25.5Dy6.5Co13FebalM1.05B0.98磁体温度稳定性和力学性能研究

本文采用速凝甩带-氢破-气流磨-取向成型-烧结回火等工序,同时添加Dy和Co元素,制备了烧结Nd_25.5Dy_6.5Co₁₃Fe_balM_1.05B_0.98磁体(Co13磁体),室温下磁能积(BH)_max=30.88 MGOe,矫顽力H_cj=19.01 kOe.与Nd₃₀Dy_1.5Co_0.5Fe_balM_1.05B_0.98(35SH)磁体相比, Co13磁体的室温磁性能略低,但温度稳定性显著提升,剩磁温度系数α从–0.136%/℃提升至–0.065%/℃(室温—180℃);居里温度T_C从310℃升高至约454℃;最高使用温度T_W从165℃提升到约200℃.力学性能测试和断口分析表明, Co13磁体中由于Co含量较高,主相晶粒发生解理断裂的比例提高...