稀土添加剂对WC—20（Fe／Co／Ni）硬质合金性能的影响

在铁镍部分低钴的基础上，采用常规硬质合金生产工艺、用不同含量的混合稀土作为添加剂进行了实验。结果表明，添加稀土可使合金硬度有较为明显的提高，对抗弯强度也有一定的影响，当稀土添加量为０．２％时，合金抗弯强度提高达５．８％左右；此外，加入稀土后，合金的耐磨性亦有所增强。     

Pr2Fe17-xAlx系列化合物的结构与磁熵变

采用熔炼法制备了Pr2Fe17-xAlx系列化合物。利用X射线衍射和MPMSXL-7型磁强计对样品相结构和磁熵变进行了研究。结果表明：Pr2Fe17-xAlx系化合物保持了Th2Zn17型菱方结构，其居里温度可通过成分微调达到室温附近；Pr2Fe17-xAlx系化合物在居里点附近发生的相变属于二级相变，并在较宽温区范围内保持了较大的磁熵变。该化合物在2．0T外场下的最大磁熵变达到纯金属Gd的60％左右，且其化学性质稳定，制冷温区宽，价格低，是一类具有较大应用潜力的新型室温磁制冷工质材料。     

Antioxidation Study of Sm（Co, Cu, Fe, Zr）z-Sintered Permanent Magnets by Metal Injection Molding

2∶17type Sm(Co ,Cu ,Fe ,Zr)zpermanent mag-nets originatedfromthe investigationinthe 1970s .Sm(Co ,Cu ,Fe ,Zr)zpermanent magnets have excellentintrinsic magnetic properties such as very high Curietemperature , high anisotropy fields , and relativelyhigh saturation magnetizations[1 ~4]. Hence the mag-nets play an i mportant role in national defence andmodernindustry .Because of the high brittleness of Sm(Co ,Cu ,Fe ,Zr)zpermanent magnets ,theirtransfor-mationinto complex,small ,precision …     

Nd11Fe71Co8V1.5Cr1B7.5合金结构与磁性能的研究

采用熔体快淬及晶化处理工艺制备Nd11Fe71Co8V1.5Cr1B7.5纳米晶合金. 运用XRD, DTA等方法研究了快淬工艺与热处理工艺对该合金纳米晶形成、晶化过程及磁性能的影响. 结果表明, 快淬速度和热处理温度都明显地影响Nd11Fe71Co8V1.5Cr1B7.5纳米晶的形成及其磁性能; 该合金在晶化过程中先后出现了3个放热峰, 分别对应软磁相α-Fe, 亚稳相和硬磁相Nd2Fe14B 3个晶化相. 快淬速度21 m*s-1制备快淬薄片经640 ℃/4 min晶化处理后, 制成的粘结磁体的最佳磁性能为 Br=0.64 T, JHc=903.5 kA·m-1, (BH)max=71 kJ·m-3.     

Influences of Niobium and Zirconium Additions on Crystallization Behaviors and Magnetic Properties of Melt-Spun （Nd, Pr）2Fe14B／α-Fe Alloys

Effects of Nb and Zr substitutions on the crystal]ization behaviors and magnetic properties of melt-spun (Nd,Pr)2Fe14B/α-Fe alloys were studied.The results show that for (Nd0.4Pr0.6)8.5Fe85.5B6 ribbons, the metastable (Nd,Pr)3Fe62B14 precipitates after the initial crystallization of α-Fe and decomposes into the final mixture of (Nd,Pr)2Fe14B and α-Fe. For(Nd0.4 Pr0.6)8.5 Fe84.5 Zr0.5 Nb0.5B6 ribbons, however,(Nd, Pr)2Fe14B and α-Fe phases precipitate simultaneously. This indicates that both Nb and Zr dopingcan avoid the formation of metastable phase and!     

GdMn2Ge2化合物的磁性和磁相变的分子场理论研究

采用交换作用的分子场理论模型对金属间化合物CdMn2Ge2的磁性、磁结构和磁相变进行了研究。理论分析和计算结果表明，CdMn2Ge2中存在5种不同类型的磁结构，外磁场以及温度的变化导致CdMn2Ge2从一种磁结构到另一种磁结构的一级或二级磁相变。计算了不同温度时GdMn2Ge2单晶的磁化曲线，并给出了外磁场沿晶轴α和c方向时的H-T磁相图，估计了Gd-Gd，Gd-Mn，层面内及层面间Mn-Mn的交换耦合参数。结果显示，要描述GdMn2Ge2的磁性，必须考虑晶格常数和温度对层面间Mn-Mn交换相互作用的影响。     

（Co78Fe22）3V中的层错和反相畴界

比较了淬火无序态（Ｃｏ７８Ｆｅ２２）３Ｖ在经过冷加工后退火和未经冷加工直接退火两种情况下的显微组织，发现在无序一有序转变过程中出现的晶体缺陷和有序态下（再结晶晶粒内）出现的是体缺陷不同，前者主要有广泛的反相畴界网络，后者主要是大量的内禀层错和孪晶，实验结果表明，有序态下超点阵内禀层错（ＳＩＳＦ）能比反相畴界（ＡＰＢ）能低得多，无序一有序转变过程中出现的位移矢量为１／６〈１１２，层错（ＳＦ）通过和Ａ     

Nd－Fe－B磁体的腐蚀对磁性能的影响

本文研究了在浸泡、湿热和大气腐蚀试验条件下，Ｎｄ－Ｆｅ－Ｂ磁体的腐蚀行为以及腐蚀对磁体磁性能的影响。实验结果表明，Ｎｄ－Ｆｅ－Ｂ合金在氯化钠水溶液中有很强的腐蚀活性。湿热试验和大气腐蚀后的腐蚀产物层有一定的保护作用。Ｎｄ－Ｆｅ－Ｂ磁体腐蚀后剩余磁感应强度Ｂｒ和最大磁能积（ＢＨ）ｍａｘ均降低，矫顽力的变化则与腐蚀介质有关。同时，讨论了Ｎｄ－Ｆｅ－Ｂ磁体腐蚀影响磁性能的作用机理。     

Preparation and Structure of Mg2-xRExNi （RE = La, Ce, Pr, Nd, Y） Ternary Alloys

A series of Mg2-xNdxNi (x =0.05, 0.1, 0.2, 0.3) alloys and Mg1.95RE0.05Ni (RE= La, Ce, Pr, Nd, Y)ternary alloys were prepared by ball milling of mixted powder of Mg, Ni, RE and sintering under the protection of argon. XRD analysis shows that Mg2-xNdxNi (x = 0.05, 0.1 ) and Mg1.95RE0.05Ni consist of single phase with the same crystal structure as Mg2Ni. While three-phase alloys including Mg2Ni, NdNi and NdMgNi4 were formed in Mg1.8Nd0.2Ni and Mg1.7Nd0.3Ni alloys respectively. The lattice constants of Mg2Ni in those ternary alloys were calculated. The decomposition of Mg2Ni occurs in the milling process of Mg2Ni and Mg1.95RE0.05Ni alloys respectively. For the latter, another earlier reaction occurs in milling process, which means that atoms of RE are separated from crystal structure of Mg2Ni and form relevant oxides by combination with oxygen existed in argon atmosphere.     

Magnetic Properties and Molecular Field Analysis of （ Ce, Nd） 2 （Fe, Si, Mn） 17 Compounds

The temperature-dependent magnetization of the ( Ce, Nd) 2 (Fe, Si, Mn) 17 intermetallic compounds were measured and analyzed by molecular field theory (MFr). The relationship between Tc and the intrasublattice coupling interactions was discussed. The two-sublattice MFT model can well describe the temperature dependence of the magnetization for all the compounds investigated. Ce ion in (Ce, Nd)2Fel7 compounds does not simply dilute the magnetic structure, but is likely present in a mixed-valence state. The substitution of Si for Fe strongly raises Tc and the mean Fe moment remains unchanged for Ce2(Si, Fe)17 compounds, and the 3d exchange coupling constant JFF increases linearly. Mn decreases Tc of Nd2(Mn, Fe)17 compound by reducing JFF。     

C—Fe—P,C—Fe—Co熔体热力学性质研究

通过拟合过剩偏摩尔自由能与组元浓度的关系式需要的参数，建立起可应用于整个液相区的组元活度解析式。应用此结构计算铁基含磷、然三元系的活度，其结果与报道的数据基本一致。并对报道的方法进行了部分修正。     

LaCo13—xMx金属间化合物的结构和磁性

在任何已知的稀土中间相化合物中,LaCo_(13)具有最高的3d金属含量,且其饱和磁化强度很高为1.03 MA/m居里温度高达1318 K,不幸的是它是立方结构,不存在适合于永磁应用所必须时各向异性。本文对LaCo_(13-x)Si_x(x=2,4)和LaCo_(13-x)Ge_x(x=2,2.5,3,4)金属间化合物的结构和磁性能进行了研究,发现对LaCo_(13-x)Si_x当x=4和LaCo_(13-x)Ge_x当x=3,4时,其晶体结构为四方结构但晶格常数a,c的差值很小。对于LaCo_(13-x)Ge_x为得到该结构所需的时效温度很严格。磁性测量发现它们的居里温度都较高,但室温饱和磁化强度随x增加大大降低。     

Fe（Ⅱ）—SO4—NH3—O2体系中铁化合物的热解重量和X光衍射的研究

Ｘ光衍射和热解重量的研究在Ｆｅ（Ⅱ）－ＳＯ４－ＮＨ３－Ｏ２体系中以不同的间隔时间得到的铁沉淀物进行。根据试验条件可得到非晶体化合物。沉淀物中铁含量在１９．８～６８％之间变化。从Ｘ光衍射图物相鉴定为；赤铁矿、针铁矿、磁铁矿。质量指标为相应的生长顺序；赤铁矿〉针铁矿〉磁铁矿。热解重量的研究表明，结晶体沉淀物的重量损失随着沉时间的延长而减少。在非结晶情况下，总重量损失（２５至８００℃）通过每隔一小时收集     

Thermoelectric Properties of （Ce, La）yFe1.0Co3.0Sb12 Compounds Syntiesized by Solid State Reaction

The filled Skutterudite compounds (Ce,La)yFexCo4-xSb12 with x= 1.0 and y=0-0.3 were synthesized by solid state reaction and Spark PlasmaSintefing (SPS) using powders of Co, Sb, Fe and rare earth Ce, La as starting materials. The thermoe-lectric properties of the compounds were also studied.It is shown that the almost single phase Skutterudite compounds (Ce, La)yFex Co4-xSb12 are synthesized at900-1000K and all samples show p-type.     

纳米晶复合Nd2Fe14B/α-Fe永磁合金磁性能研究

采用快淬和晶化退火法制备了成分为Nd8.5Fe74.5Co5Cu1Nb1Zr3Cr0.5B6.5的纳米晶复合永磁合金.研究了制备过程中快淬速度和退火温度对合金磁性能和组织结构的影响.结果表明,快淬速度为16.7m/s,合金样品经690℃/4min的晶化处理后,制成的粘结磁体可得到较优异的综合磁性能Br=0.65T,JHc=708.4kA/m,(BH)max=72.0kJ/m3.     

Influence of Non—Magnetic Substitutional Atoms on Spontaneous Moment and Curie Temperature of Ce2Co17Compounds

The structure and magnetic properties of Ce2Co17-xMx(M=Ga,Al and Si)compounds for Mcomcentrations up to x=5 were studied by means of X-ray diffraction and magnetic measurements,The experimental results show that the Curie temperatures and Co spontaneous magnetization decrease significantly with increasing the addition of non-magnetic substitutional atoms,and that Si which has a minimum solid solubility ic Ce2Co17causes a largest reduction of Curie temperature,spontaneous magnetization and moment perCo atom compared with Ga and Al.