ABSTRACTS from TRANS NFsoc（Chineseedition） Vol．4，No．4，Dec．1994 A－Geology and Mining；B－Mineral Processing and Metallurgy；C－Materials Science and Engineering

ＡＢＳＴＲＡＣＴＳｆｒｏｍＴＲＡＮＳＮＦｓｏｃ（Ｃｈｉｎｅｓｅｅｄｉｔｉｏｎ）Ｖｏｌ．４，Ｎｏ．４，Ｄｅｃ．１９９４Ａ－ＧｅｏｌｏｇｙａｎｄＭｉｎｉｎｇ；Ｂ－ＭｉｎｅｒａｌＰｒｏｃｅｓｓｉｎｇａｎｄ　Ｍｅｔａｌｌｕｒｇｙ；Ｃ－Ｍａｔｅｒｉａｌｓ　Ｓｃ...     

Calculation on Relation of Energy Bandgap to Composition and Temperature for Ga_xIn_（1－x）As_（1－y）Sb_y

ＣａｌｃｕｌａｔｉｏｎｏｎＲｅｌａｔｉｏｎｏｆＥｎｅｒｇｙＢａｎｄｇａｐｔｏＣｏｍｐｏｓｉｔｉｏｎａｎｄＴｅｍｐｅｒａｔｕｒｅｆｏｒＧａ＿ｘＩｎ＿（１－ｘ）Ａｓ＿（１－ｙ）Ｓｂ＿ｙＴｉａｎＹｕａｎ，ＺｈａｎｇＢａｏｌｉｎ，ＪｉｎＹｉｘｉｎ，ＺｈｏｕＴ...     

High T_cHoBa_2Cu_3O_（7－δ） Thin Films Deposited on （100） Y_2O_3 Stabilized ZrO_2 Substrates by Sputte

ＨｉｇｈＴ＿ｃＨｏＢａ＿２Ｃｕ＿３Ｏ＿（７－δ）ＴｈｉｎＦｉｌｍｓＤｅｐｏｓｉｔｅｄｏｎ（１００）Ｙ＿２Ｏ＿３ＳｔａｂｉｌｉｚｅｄＺｒＯ＿２ＳｕｂｓｔｒａｔｅｓｂｙＳｐｕｔｔｅｒｉｎｇＰｅｎｇＺｈｅｎｇｓｈｕｎ，ＹａｎｇＢｉｎｇｃｈｕａｎａｎｄＷａｎ...     

快速凝固Al－8．32Fe－3．4Ce合金的热稳定性和组织结构的关系

研究了快速凝固Ａｌ－８．３２Ｆｅ－３．４Ｃｅ高温铝合金在不同温度长时间热暴露后的室温力学性能和相析出。实验结果表明Ａｌ－８．３２Ｆｅ－３．４Ｃｅ一直到３１５℃有较好的热稳定性，热稳定性和相析出及相长大有密切关系。不同热暴露后得到的析出相分别为Ａｌ＿（１３）Ｆｅ＿４，Ａｌ＿ｍＦｅ，Ａｌ＿８Ｃｅ，Ａｌ＿（１３）Ｆｅ＿３和Ａｌ＿（１６）Ｃｅ＿３Ｆｅ等等。其中Ａｌ＿８Ｃｅ和Ａｌ＿（１３）Ｆｅ＿３Ｃｅ在文献中未见报道。     

Fe_（73．5）Cu_（1．0）Nb_（3．0）Si_（13．5）B_9纳米软

从Ｈｏｐｋｉｎｓｏｎ效应及Ｘ光衍射技术研究了Ｆｅ（７３．５）Ｃｕ（１．０）Ｎｂ（３．０）Ｓｉ（１３．５）Ｂ９纳米软磁合金的居里温度特性。随晶化退火温度Ｔａ的提高，合金中αＦｅ－Ｓｉ纳米晶相的居里温度提高，但低于相同Ｓｉ含量下的常规Ｆｅ－Ｓｉ合金，且与显微组织结构有关，当Ｔａ较低时，合金中非晶相的居里温度与原始非晶合金基本相同。但其Ｈｏｐｅｉｎｓｏｎ峰宽化，Ｔａ＞７８３Ｋ后，其Ｈｏｐｋｉｎｓｏｎ４消失，无法判断居里温度。认为居里温度的上述特性与合金晶粒的小尺寸特性及元素成分分布特性有关。     

Sm_3（Fe_（0．85）Cr_（0．15）_（29）Ny合金的结构和磁性

Ｓｍ＿３（Ｆｅ＿（０．８５）Ｃｒ＿（０．１５）＿（２９）Ｎｙ合金的结构和磁性研究了氮含量和退火条件对Ｓ，。（Ｆｅｏ．８。Ｃｉｏ．１。）２．Ｎｙ合金结构和磁性的影响。合金由感应炉熔炼，并经高温均匀化处理，然后磨成２０～４５卜ｍ粗粉。粉末在０．ＳＭＰａ氮...     

Electron Microscopy Studies of Magnetron Sputtered YBa＿2Cu＿3O＿（7－δ） Thin Films

ＥｌｅｃｔｒｏｎＭｉｃｒｏｓｃｏｐｙＳｔｕｄｉｅｓｏｆＭａｇｎｅｔｒｏｎＳｐｕｔｔｅｒｅｄＹＢａ＿２Ｃｕ＿３Ｏ＿（７－δ）ＴｈｉｎＦｉｌｍｓＳｈａＷｅｉ沙维（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｅｒｉａｌｓ，ＩｍｐｅｒｉａｌＣｏｌｌｅｇｅ，ＰｒｉｎｃｅＣｏ...     

Quantum Chemical Calculation on Preparation of YBa＿2Cu＿3O＿（7－δ） Powders by Hydrolysis of Metal Alkoxides

ＱｕａｎｔｕｍＣｈｅｍｉｃａｌＣａｌｃｕｌａｔｉｏｎｏｎＰｒｅｐａｒａｔｉｏｎｏｆＹＢａ＿２Ｃｕ＿３Ｏ＿（７－δ）ＰｏｗｄｅｒｓｂｙＨｙｄｒｏｌｙｓｉｓｏｆＭｅｔａｌＡｌｋｏｘｉｄｅｓＹｉｎＺｈｏｕｌａｎ；ＬｉＸｉｎｈａｉ；ＺｈａｏＱｉｎｓｈｅｎｇ；...     

铱—钼酸盐—丁基罗丹明B—PVA_（－124）体系光度法测定铱

在聚乙烯醇（ＰＶＡ）存在下，Ｉｒ（Ⅳ）与钼酸盐和丁基罗丹明Ｂ（ＢＲＢ）形成离子缔合物。测定Ｉｒ的适宜条件为Ｃ＿（ＨＣιＯ４）＝１．３ｍｏｌ／Ｌ，Ｃ＿（ＭｏＯ＿４）￣（２－）＝１．１×￣（－３）ｍｏｌ／Ｌ，Ｃ＿（ＢＲＢ）＝３．８×１０￣（－５）ｍｏｌ／Ｌ，ＰＶＡ０．０８％。离子缔合物的最大吸收位于５７０ｎｍ，摩尔吸光系数ε值为８．７５×１０￣５Ｌ·ｍｏｌ￣（－１）·ｃｍ￣（－１），至少可稳定一周，Ｉｒ量在０～２．５μｇ／２５ｍｌ服从比尔定律，测定极限为８．３ｎｇ／ｍｌ（ｎ＝１１），对于０．０８μｇ／ｍｌＩｒ测定的相对标准偏差为２．８％（ｎ＝８）。考察了４１种共存离子的影响，其他贵金属和Ｓｂ（Ⅱ）。Ｇｅ（Ⅳ）、Ｓｉ（Ⅳ）干扰，需采用火试金分离。本法已用于某些岩矿和冶金中间产品中Ｉｒ的测定，结果满意。用平衡移动法测定缔合物的摩尔比为Ｉｒ：ＢＲＢ＝１：４，探讨了反应机理。     

Fe_（1－x）（Nd_2Fe_（14）B）_x快淬合金的磁性能

系统研究了低Ｎｄ低Ｂ的Ｆｅ１－ｘ－（Ｎｄ２Ｆｅ１４Ｂ）ｘ快淬合金的制备工艺和磁性能。通过优化热处理工艺和元素替换，控制α－Ｆｅ和Ｆｅ３Ｂ软磁相的析出和长大，获得较高的磁性能。该系列Ｎｄ３Ｆｅ８６Ｖ２Ｂ４合金具有最佳性能．Ｂｒ＝９．７ｋＧｓ，ＪＨＣ＝４．３ｋＯｅ，（ＢＨ）ｍａｘ＝１１．４ＭＧＯｅ。     

Crystallization kinetics and induced magnetic properties of bulk （Fe,Co）-Zr-Nd-B metallic glass

Crystallization kinetics and phase transformation of bulk Fe64 Co7 Zr6 Nd3B20 metallic glass were studied by X-ray diffractometry (XRD), differential scanning calorimetry (DSC) and transmission electron microscopy (TEM). Based on the Kissinger analyses, the activation energies for the nucleation and growth during the first, second and third crystallization-stages of the metallic glass are determined to be 294, 475 and 365 kJ/mol, respectively, and the activation energy for the glass transition is determined to be 1 242 kJ/mol. The Johnson-Mehl-Avrami (JMA) analysis under the isothermal condition reveals that the crystallization process is a three-dimensional controlled growth of nuclei at a constant nucleation rate. The crystalline grains are in the size of less than 50 nm after the selected annealing treatments. In the completely crystallized state, the alloy exhibits the maximum coercivity (Hc) of 34.8 kA/m and corresponding energy product of 11 kJ/m^3.     

Zr52.5Ni14.6Al10Cu17.9Ti5块体玻璃合金等温晶化与结构转变

对采用射流成形方法制备了Ｚｒ５２．５Ｎｉ１４．６Ａｌ１０Ｃｕ１７．９Ｔｉ５块体玻璃合金进行等温退火,利用Ｘ射线衍射和ＳＥＭ及ＴＥＭ分析了块状玻璃态合金等温晶化时相转变及组织转变。     

EFFECT OF HEAT TREATMENT ON POSITRON ANNIHILATION OF GLASSY Bi_(1.6)Pb_(0.4)Sr_(1.9)Ca_2Cu_(3.1)O_y

Effects of isochronal annealing on the positron annihilation of glassy Bi_(1.6) Pb_(0.4) Sr_(1.9)Ca_2Cu_(3.1)O_y(BPSCCO)have been reported.It is shown that the crystallization influencesobviously the positron annihilation characteristics of BPSCCO.A maximum is found inthe region of crystallization temperature in curves of mean lifetime and peak/wing ratio,one of Doppler Iineshape parameter,with annealing temperature;the bulk lifetime ofpositron annihilation in the glassy state is longer than that in the crystalline one.Positronannihilation spectroscopy could be used for studying structure of glassy BPSCCO andits change with heat treatment.     

Mg_(80)Cu_(15)Y_5合金的非晶形成能力及晶化行为

采用单辊快速凝同法制备出厚约40μm的Mg_(80)Cu_(15)Y_5非品合金薄带,利用XRD、DSC、TEM和HRTEM研究了非品合金的非品形成能力和晶化行为,分析了品化对合金组织结构与性能的影响.结果表明:Mg_(80)Cu_(15)Y_5合金的过冷液态温度区间△T_x和约化玻璃转变温度T_(rg)分别为55K和0.58,表明其具有较强的非晶形成能力;该合金在退火温度高于473 K后发牛明显晶化,从非品基体中析出 Mg_2Cu、Cu_2Y和Mg晶体相;随着退火温度的升高,合金的硬度呈现出先升高后降低的变化趋势,这与纳米品体相颗粒的弥散析出、重溶及粗化有关.     

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.     

Direct TEM Observation of Phase Separation and Crystallization in Cu_(45)Zr_(45)Ag_(10)Metallic Glass

The structural evolution of Cu_(45)Zr_(45)Ag_(10) metallic glass was investigated by in situ transmission electron microscopy heating experiments. The relationship between phase separation and crystallization was elucidated. Nucleation and growth-controlled nanoscale phase separation at early stage were seen to impede nanocrystallization, while a coarser phase separation via aggregation of Ag-rich nanospheres was found to promote the precipitation of Cu-rich nanocrystals.Coupling of composition and dynamics heterogeneities was supposed to play a key role during phase separation preceding crystallization.     

Phase Separation and Crystallization Induced by Electron Irradiation in Nanoscale Fe_(56.5)Mn_(11)Cr_(8.5)Ni_4Si_(10)C_(10) Metallic Glass

A nanoscale Fe_(56.5)Mn_(11)Cr_(8.5)Ni_4Si_(10)C_(10) metallic glass was irradiated by electron beam in a 200 kV transmission electron microscope.Structure evolution in the metallic glass was investigated in situ during continuous irradiation,where phase separation was observed after irradiation for 5 min and crystallization was observed after 33.5 min.Based on the analysis of irradiation effect,atomic displacement is believed to be the main reason for the structure rearrangement.Accumulation of atomic displacement increases the energy of the sample and promotes atomic diffusion during transformation.On the other hand,the large specific surface area of the sample also contributes to increasing free energy and atomic diffusion.     

部分非晶态Fe_(33)Zr_(67)合金条带的表观晶化动力学

利用示差扫描量热卡计（ＤＳＣ），结合Ｘ射线衍射分析（ＸＲＤ）及透射电子显微镜分析（ＴＥＭ）等实验，研究了部分非晶态Ｆｅ３３Ｚｒ６７合金条带的晶化动力学结果表明：晶化过程为晶粒长大过程所控制，尽管在条带中淬态核分布明显不均匀，与经典Ａｖｒａｍｉ分析的基本假设相矛盾，但该晶化过程仍然与ＪＭＡ反应动力学结论一致．     

Multiwalled carbon nanotube nucleated crystallization and reinforcement in poly (vinyl alcohol) composites

One of the fastest growing areas of nanotube research is the study of polymer-nanotube composite materials. These materials utilize the excellent strength of carbon nanotubes that has been evident but difficult to harness in the past and show impressive increases in strength relative to the polymer. It is suspected that many of the physical properties observed in these composites are related to the formation of crystalline polymer coatings around the nanotubes in solution. The work presented here addresses this issue by doping a semi-crystalline polymer, poly (vinyl alcohol), with multiwalled carbon nanotubes. Dynamic mechanical analyzer (DMA) measurements of thin films identified a three- to five-fold increase in the Young's modulus of the polymer depending on nanotube type. Dynamic differential scanning calorimetry (DSC) of thin films shows that the increase in modulus is accompanied by an increase in polymer crystallinity. In addition, the results verify that multiwalled carbon nanotubes nucleate crystallization of the polymer and a link between polymer crystallinity and composite reinforcement is established. Furthermore, transmission electron microscopy (TEM) images confirm an excellent dispersion and wetting of the nanotubes in the polymer solution providing visual evidence of matrix reinforcement.     

Microstructure evolution in nanocrystalline NiTi alloy produced by HPT

A slightly Ni-rich nano-NiTi alloy, deformed by high-pressure torsion (HPT) was investigated. By HPT, almost complete amorphization of initial B2 NiTi is obtained. Crystallization and microstructure evolution during isothermal treatment were investigated by differential scanning calorimetry (DSC) and transmission electron microscopy.The DSC signals observed during continuous heating experiments indicate an unusually large separation between the crystallization and the growth stages. A detailed analysis of the evolution of the enthalpy release upon annealing reveals reproducibly non-monotonous trends with annealing time that cannot be explained solely by growth of crystalline volume fractions. The size of nanocrystals increases dramatically after annealing for 5 h. The effective activation enthalpies for stress relaxation (along with crystallization) and grain growth were estimated at 115 and 289 kJ/mol, respectively. The results are discussed with respect to the intricate interdependencies between synthesis and thermal processing pathways and the evolution of the nanoscale microstructure.