Y2（Fe.095Al0.05）14B的中子衍射研究

用中子衍射对永磁合金Y_2(Fe_(0.95)Al_(005))_(14)B进行了测量。结果表明:其仍为Nd_2Fe_(14)B型四角结构,空间群为P42/mnm;Al进入晶体结构之中并择优占据4c及8j_2晶位。对Al的择优占位与磁性的关系进行了初步的讨论。     

Nd_2(Fe_(0.9)Si_(0.1))_(14)B的中子衍射研究SCIEI

本文用中子衍射对Nd_2(Fe_(0.9)Si_(0.1))_(14)B在室温及77K进行了测量,用衍射峰的形状分析法进行了数据拟合。结果表明,在室温,Si择优占据4c,8j_1及16k_2晶位;Nd与Fe的磁矩平行于C轴排列。在77K,Si仍择优占据上述三个晶位。算得的Nd磁矩的方向偏离C轴37.8°。     

Y2Fe17—xMnx的结构和磁性

Ｘ射线衍射证实了Ｙ２Ｆｅ１７－ｘＭｎｘ的结构与Ｙ２Ｆｅ１７相同Ｙ２Ｆｅ１７－ｘＭｎｘ化合物晶格常数，居里温度，饱和磁化强度和研究结果表明：晶格常数并非随Ｍｎ含量的增加而连续增大，而是在ｘ＝２．０处出现一最小值。     

CREEP FRACTURE OF INTERMETALLIC COMPOUND(Fe_(60)Ni_(40))_3(V_(98)Ti_2)

The creep fracture behavior of intermetallic compound(Fe_(60)Ni_(40))_3(V_(98)Ti_2)has been studied.The variation of dislocation substructure was observed with TEM in the process ofsteady-state creep.It is found that there exists a large amount of stacking faults,dislocationpairs and also high density dislocation networks.SEM analysis of section near fracture sur-face points out that the intergranular crack due to coalescence of small cavities is the maincreep fracture mechanism of(Fe_(60)Ni_(40))_3(V_(98)Ti_2).     

Y3（Fe,Mo）29金属间化合物的结构特性

使用Ｒｉｅｔｖｅｌｄ方法对Ｙ３（Ｆｅ,Ｍｏ）２９金属间化合物的Ｘ射线衍射谱和中子衍射谱进行分析,得出了Ｙ３（Ｆｅ,Ｍｏ）２９金属间化合物Ａ２／ｍ空间群的结论。坐标变换结果表明：Ｙ３（Ｆｅ,Ｍｏ）２９金属间化合物的空间结构是１：１２和２：１７的混合特性。     

Y_3(Fe,M0)_(29)金属间化合物的结构特性

使用Rietveld方法对Y3（Fe,Mo）29金属间化合物的X射线衍射谱和中子衍射谱进行分析,得出了Y3（Fe,Mo）29金属间化合物属A2／m空间群的结论.坐标变换结果表明Y3（Fe,Mo）29金属间化合物的空间结构是1∶12和2∶17的混合结构     

STRUCTURAL REFINEMENT FOR Nd_2(Fe_(0.9)Si_(0.1))_(14) B FROM NEUTRON DIFFRACTION MEASUREMENT

Neutron diffraction measurements on Nd2(Fe0,Si0 ,)14B at room temperature and 77 K were performed. Data analysis using profile refinement was carried out. The results show that at room temperature Si atoms occupy preferentially 4c, 8j, and I6k2 sites, and the magnetic moments of bath Nd and Fe are parallel to C—axis. At 77 K, the site occupations remain unchanged as in room temperature, while the calculated Nd magnetic moment direction has an angular deviation of 37.8 ° from C—axis.     

间隙碳原子对（Er1—xSmx）2Fe17Cy化合物形成,结构与磁性的影响

用快淬方法制备了单相（Ｅｒ１－ｘＳｍｘ）２Ｆｅ１７ｃｙ（ｘ＝０．２，ｙ≤３．０；ｘ＝０．５，ｙ≤２．０）化合物，研究了它们的形成、结构、稳定性及内禀磁性。结果表明，它们在高温是稳定的，随碳含量的增加，晶体结构由六角的Ｔｈ２Ｎｉ１７型向菱方的Ｔｈ２Ｚｎ１７型转变。间隙碳原子的引入导致了单胞体积的膨胀、室温饱和磁化强度和Ｃｕｒｉｅｉ温度的增加。当ｙ≥１．０时，（Ｅｒ１－ｘＳｍｘ）２Ｆｅ１７Ｃｙ样品在室     

THERMAL DEMAGNETIZATION AND RANDOMNESS OF DOMAIN NUCLEATION OF SINGLE PHASE Nd_2 Fe_(14) B

Based on the observation of temperature variation of both domain structure and magnetic con-trast.the thermal demagnetization and randomness of domain nucleation was discussed.     

金属间化合物（Fe60Ni40）3（V98Ti2）的蠕变断裂

对有序金属间化合物(Fe_(60)Ni_(40))_3(V_(98)Ti_2)的蠕变断裂行为进行了初步研究。用透射电镜观察了稳态蠕变过程中位错亚结构的变化,发现存在大量的堆垛层错和成对位错以及较高密度的位错网络。对断口及近断口剖面的扫描电镜观察指出,晶界上空洞所形成的沿晶断裂是(Fe_(60)Ni_(40))_3(V_(98)Ti_2)蠕变断裂的主要机制。     

MAGNETIC PROPERTIES AND CRYSTALLIZATION OF RAPIDLY QUENCHED(Fe_(1-x)Ga_x)_(77.5)Nd_4B_(18.5) ALLOYS

The Curie temperature increases but crystallization temperature decreases with the in-crease of Ga content,x,of amorphous(Fe_(1-x)Ga_x)_(77.5)Nd_4B_(18.5) alloys.The averagemagnetic moment of Fe atoms is almost a constant.By X-ray diffraction and ther-momagnetic measurements,the crystalline phases of the alloys,an unknown phase andα-(Fe,Ga)besides Fe_3 B as major one,were identified.The relationship between roomtemperature coercive field and Ga.content was also studied.     

（Sm_（1－x）Y_x）_2Fe_（17）N_y的Mossbauer谱研究

通过Ｍｏｓｓｂａｕｅｒ谱等研究（Ｓｍ１－ｘＹｘ）２Ｆｅ（１７）Ｎｙ的磁性。结果表明：Ｓｍ次格子的单轴各向异性较强，对总的各向异性贡献起主导机制；Ｙ原子的择优占位导致晶体结构的变化，而对各向异性的影响较小。     

压力铸造(Al_(63)Cu_(25)Fe_(12))_p/AZ91复合材料的研究

在CO2/SF6气氛保护下,采用压铸的方法将小于74μm的Al63Cu25Fe12准晶粉末注入到熔融的AZ91镁合金中,在720℃和一定的压力下保压30min,制备了新型的体积分数为10%的(Al63Cu25Fe12)p/AZ91镁基复合材料。采用扫描电镜(SEM)和能谱分析仪(EDAX)分析了复合材料中准晶颗粒与基体金属之间的反应,并且研究了复合材料不同于基体材料的热处理工艺过程和性能的关系。结果表明,在复合过程中,准晶I相出现了分解,分解出的自由Cu向基体扩散并与基体中的Al发生了反应,生成的金属间化合物分布在准晶颗粒的周围,同时Mg向颗粒中浸渗,填充到颗粒的孔隙中;复合材料具有不同于基体镁合金的固溶时效特征,需要更长的时间才能达到时效峰值;复合材料经过热挤压和热处理后的力学性能显著提高,抗拉强度从AZ91铸态材料的189.54MPa提高到359.38MPa,但塑性有所降低。     

非晶（Fe0.99Cu0.01）78Si9B13合金等温晶化动力学

利用DSC,结合XRD,TEM实验,研究了(Fe_(0.99)Cu_(0.01))_(78)Si_9B_(13)非晶合金等温晶化动力学,结果表明:该合金等温晶化按两个阶段进行,分別析出α-Fe(Si)固溶体和Fe_2B化合物利用局域Avrami指数的概念分析了两相的形核长大方式。并作出了出合金晶化的“C”曲线,通过对两相晶化激活能的分析得出:α-Fe(Si)相较Fe_2B相容易晶化析出,同时,Cu元素的添加有助于改善α-Fe(Si)相的形貌。     

氢作用下Nd14Fe73Co6B7的相转变

利用X射线衍射、透射电子显微镜、扫描电镜及磁测量技术观察和分析了Nd_(14)Fe_(73)Co_6B_7合金于770℃吸氢后相结构组成与变化发现铸锭中的Nd_2Fe_(14)B基体吸氢后分解成约为0.1μm的NdH_2,α-Fe和Fe_2B三相混合物,脱氢后重新结合的Nd_2Fe_(14)B相尺寸约为0.3μm;铸锭中分布在基体相周围的富Nd边界相在吸氢时扩散入Nd_2Fe_(14)B基体,在脱氢过程中保留下来,均匀地分布在由若干Nd_2Fe_(14)B细小晶粒组成的晶粒团周围     

MAGNETIC PHASE DIAGRAM OF SmMn_2(Ge_(1-x)Si_x)_2 SYSTEM

1.IntroductionTheternaryRMn2X2compounds(Risrareearth,andXisGeorSi)crystallizeinthebodycenteredtetrag0nalThCr2Si2-typestructurewithspacegr0upI4/mmm,inwhichtheR,TandXatomsoccuPythe2a,4dand4csites,respectivelyl1t2].Theyexhibitillterestingmagneticpr0perties['].InSmMn2Ge2tlireedifferentmagneticorderingtypeshavebeendetermined:ferromagnetismfor153K相似文献   

PHASE COMPONENT AND CURIE TEMPERATURE OF Nd_4(Fe_(1-x)Cr_x)_(77.5)B_(18.5)ALLOYS

1.IntroductionThenewhard-magneticNdFeBall0yswithlowNdc0ncentration(35at.%)havebeenobtainedbycrystallization0fam0rphous.ibbo.sI1-3].Theirmagneticpr0pertiesatr0omtemperatureareasfollows:coercivityHc=16O-24OkA/m,remanenceB,=1'2-1.25T,andmagneticenergy(BH).ax=64108kJ/m'.ThevaluesofB.and(BH).axaremuchhigherthanth0se0fthewidelyusedanis0tropic(Ba,Sr)Fe12Ol9ferritesandAlNiC0alloys.Inpreyi0uspapers['-'1,wehavereportedthestructuralandmagneticpr0perties.Recentlywestudiedtheinfluenceofthesubstit…     

TRANSFORMATION OF Nd_(14)Fe_(73)Co_6B_7 ALLOY UNDER HYDROGEN TREATMENT

The phase constitution and variation of Nd_(14)Fe_(73)Co_6B_7 alloy after hydriding and subsequentdehydriding treatment at 770℃ have been investigated respectively by means of X-raydiffraction,SEM,TEM and magnetic measurement techniques.The original coarse,as castgrain structure,is dissolved into α-Fe,Nd hydride and Fe_2B mixture with average dimensionof 0.1 μm,during hydriding process,and subsequently the triphase mixture recombined intofinely unique Nd_2Fe_(14)B phase with dimension of 0.3 μm by desorbing the hydrogen.It wasfound that the Nd-rich phase distributed at the boundary of as-cast grain structure diffusedinto matrix Nd_2Fe_(14)B grain during hydriding.It remains during dehydriding and distributehomogeneously around some colonies composed of fine grains of Nd_2Fe_(14)B.     

Nd_2(Fe_(1-x)M_x)_(14)B(M=C,Si)合金的磁性

本文研究了Nd_2(Fe_(1-x)M_x)_(14)B的磁性。少量类金属原子C和Si取代部分Fe,能形成四方结构,且具有单轴各向异性。碳取代Fe,使化合物的Curie温度降低,低温下粘结体样品的内禀矫顽力减少;而Si对Fe的取代可使Curie温度升高,并在x=0.15附近达到极大值。含Si样品在0≤x≤0.10范围内,矫顽力显著增加,室温下从x=0的62.7kA/m增加到x=0.06的138.7 kA/m,并且在x=0.06附近,剩磁有一个极值,饱和磁化强度减少不多。     

MAGNETIC PROPERTIES OF Nd_2(Fe_(1-x)M_x)_(14)B(M=C,Si)ALLOYS

The magnetic properties of Nd_2(Fe_(1-x)M_x)_(14)B(M=C and Si) compounds have been investi-gated.Substituting Fe by small amount of metalloid C and Si atoms,the compounds are intetragonal structure and have uniaxial anisotropy.The substitution of C for part of Fe de-creases the Curie temperature of the compounds and the intrinsic coercivity of bond samples atlow temperature.The replacement of Fe by Si makes the Curie temperature increase with amaximum at the vicinity of x=0.15.When the range of the content of Si is 0≤x≤0.10,thecoercivity distinctly increases at room temperature.from 62.7 kA/m at x=0 to138.7kA/m at x=0.06,where the residual magnetization has a maximum:in the mean timethe saturation magnetization decreases only by a small amount.