Abstract:通过对钛酸铅陶瓷气相扩渗稀土元素,制备了导电陶瓷材料。通过X射线衍射、电子探针X射线能谱和扫描电镜测试分析,表明稀土元素La,Ce,Gd,Sm等均已渗入到PbTiO3陶瓷体相中,并生成了新的化合物La5O7NO3,La2C2O2,Gd2O3,La2Ti6O15,SmO和CeTi21O38,并使扩渗后的PbTiO3基陶瓷的导电性能发生了十分显著的变化,其室温电阻率从纯PbTiO3陶瓷的2.0×1010?·m下降为0.2?·m,而且随着温度的变化,晶粒电阻呈现明显的PTCR效应,而晶界电阻随着温度的升高,呈急剧连续降低状态,总电阻的变化规律与晶界电阻的变化相类似,试样总电阻的PTCR效应已不存在,已表现出导电体特征。

Abstract:Luminescence fibers of Eu3+ doped ZnO-MgO-La2O3-B2O3 were prepared by solid state reaction at high temperatures. Their diameters were in the range of 0.01 mm~0.30 mm and their lengths were more than 10 m. Their curves of stress-strain were measured by the axial extension test. The change of the yield surface and the constitutive relations of the stress-strain were investigated based on the theory of elastic-brittle-plastic. Their elastic modulus, intensity, stress peak load, strain of stress intensity, elongation ratio to rupture of the axial extension, and brittleness index of the material were calculated. It is found that their strong emission band of Eu3+ with a maximum at 614 nm belongs to the electric dipole transition of 5D0-7F2 and the emission at 581 nm with 40% relative intensity to 614 nm belongs to magnetic dipole transition of 5D0-7F1. The host emission peak presenting to 438 nm overlaps its excitation band. The result shows that their elastic modulus are higher than those of common glass and marble, close to hard aluminum alloy and rolled aluminum. Their stress intensity and peak load are relatively big.

Abstract:The microstructure, optical absorption properties and luminescence function of GaN thin films grown on the sapphire substrate with the buffer layer of GaN by MOCVD have been studied by means of XRD, TEM, infrared transmission spectrum, and photoluminescence. The XRD results show that the crystal of GaN is hexagonal wurtzite structure. The thin films have perferred orientation in c axis with very high quality. The TEM images of cross-sectional specimen show that the thicknesses of every layer in the superlattices are uniform with the average period of 13.3 nm, but there are high-density dislocations in the superlattices region. With the related optical experimental data, it had been found that the optical absorption edge was at about 370 nm. The theory calculation indicates that the five samples are direct transition semiconductor with band-gaps of about 3.4 eV. The refractive indexes of the samples increase with the photon energy enhance and decrease with the wavelength increasing. The results show that the extinction coefficients have the minimum at 370 nm. Photoluminescence test results show that the superlattice has preferable luminescence property and a yellow luminescence is found.

Abstract:运用盐-金属反应法制备了亚微米TiB_2 颗粒增强铝基复合材料(TiB_2/AC8A)。TiB_2 颗粒通过钛盐和硼盐与铝合金反应原位生成。对复合材料进行了显微组织观察和高温蠕变性能实验。原位TiB2颗粒的尺寸约为0.5 μm,近似呈球形。TiB_2/AC8A 复合材料具有优异的高温蠕变性能。10 ω/% TiB2原位颗粒(~0.5 μm)增强AC8A 复合材料的蠕变抗力比10 φ/% SiCp(1.7 μm)外加颗粒增强Al 复合材料至少要高两个数量级。10 ω/% TiB_2/AC8A 复合材料表现出高的名义应力指数(11.7~12.5)和名义激活能(265 kJ/mol),其稳态蠕变数据能够用应力指数为8 的亚结构不变模型和门槛应力来解释。TiB_2/AC8A 复合材料的蠕变断裂行为符合Monkman-Grant 关系式。

Abstract:This paper reports that nano- La0.7Pb0.3FeO3 powders can be used as a new type of gas-sensing material for detecting CO. The La0.7Pb0.3FeO3 powders were prepared by a citric method. The powders are characterized by X-ray diffraction, showing that the La0.7Pb0.3FeO3 is still perovskite phase with orthorhombic structure and its crystallite size is about 17 nm, smaller than that of LaFeO3. The La0.7Pb0.3FeO3 is a kind of p-type semiconductive material, and its conductivity is higher than that of LaFeO3. The CO sensitivity of La0.7Pb0.3FeO3-based sensor is investigated. We found that La3+ partly substituted by Pb2+ in LaFeO3 can enhance its sensitivity for CO gas.

Abstract:通过液态原位反应合成制备MgO/Mg2Si增强Mg-Li基复合材料,利用TEM对增强相形态及界面结构进行了观察。实验结果表明,复合材料中增强粒子与基体界面结合良好,无反应物生成。确定了增强粒子与基体的界面取向关系,MgO与基体α相的晶体学关系为[100]MgO‖[4043]α,(011)MgO‖(1210)α;Mg2Si与基体β相的晶体学关系为[310]Mg2Si‖[411]β,(131)Mg2Si‖(001)β。

Abstract:The intermetallic-compounds-strengthened composite was reaction synthesized by hot pressing sintering the mixture of ball-milled Ti-Al powder and TiC+Al2O3 powder. According to the X-ray analysis and thermal analysis (DSC) of the powder and its components analysis of the sintering product, it shows that there are no other compounds but Ti3Al.Through thermodynamic calculation, the author analysized the reaction synthesized process, and found the gradual synthesis process from TiAl3 to TiAl, then to Ti3Al controlled by the diffusion under lower temperature and the formation mechanism of intermetallics compounds at high temperature, and it is in stable state at the interface between matrix and strengthening phases.

Abstract:TiO2 films were prepared by dc reactive magnetron sputtering. The UV-Vis spectra and PL spectra of samples before and after heat treatment were studied in detail. An absorption peak (496 nm) in UV-Vis spectra and an emission shoulder (496.5 nm) in PL spectra are observed clearly. The analysis of X-ray photoelectron spectroscopy (XPS) indicates that the lattice oxygen can be removed by heat treatment to form the Ti3+ and oxygen vacancies. Taking the XPS analysis and theory calculation into consideration together, it can be concluded that the absorption peak (496 nm) in UV-Vis spectra and the emission shoulder (496.5 nm) in PL spectra are attributed to the d-electron transition of Ti3+ in TiO2 films.

Abstract:The micro-arc oxidization is an efficient and pollution-free technique of surface processing and can form in situ a ceramic layer on the surface of nonferrous metal. In this paper, the micro-arc oxidization ceramic layer was formed on the surface of TiAl alloy by using a self-designing pulse power supply equipment of micro-arc oxidization. The oxidation dynamics of the ceramic layer on the surface of TiAl alloy was studied in the cycle high temperature condition and the experimental results show that the oxidation dynamics curve of TiAl alloy micro-arc oxidization ceramic layer submitted a parabolic function, which indicates that the ceramic layer can protect the TiAl alloy. Moreover, the effect of SiO32- on the characteristics of the ceramic layer was also studied, the results show that the working temperature with a micro-arc oxidization ceramic layer can be increased to 1273 K after adding SiO32- in the solution of the micro-arc oxidization. Analyzing by SEM and XRD test, the TiAl alloy ceramic layer contained 80 percent Al2TiO5, 11 percent TiO2 and 9 percent SiO2, which indicates that the addition of SiO2 can effectively restrain the decomposition of Al2TiO5 at high temperature and thus significantly increase the anti-oxidation of the TiAl alloy.

Abstract:采用SiC/Si3N4陶瓷先驱体聚硅氮烷连接反应烧结碳化硅陶瓷,研究了连接温度、连接压力、浸渍/裂解增强处理对连接强度的影响。结果表明:在1100℃~1400℃温度范围内,连接强度先升高后降低;连接过程中施加适当的轴向压力可提高连接层致密度;浸渍/裂解增强处理可大幅度提高接头强度。当连接温度为1300℃,连接压力为15kPa,经3次增强处理的连接件抗弯强度达最大值169.1MPa。这种连接件的断口表面粘有大量SiC母材。由XRD研究表明,随着温度的逐步升高,聚硅氮烷的裂解产物发生了由非晶态向晶态的转变。微观结构及成分分析显示:连接层为厚度2μm~3μm的SiCN无定形陶瓷,其结构较为均匀致密;连接层与基体间界面接合良好。

Abstract:Performance of Ni-MH batteries for the Mm(NiCoMnAl)5 alloy prepared by casting and melt-spinning techniques as negativeelectrode was studied. Different preparation methods show little influence on the capacity and internal resistance of the batteries, whiletheir discharge voltage plateau decreases after annealing the as-cast alloy and also decreases with increasing solidification rate of the alloysprepared by melt-spinning technique. The internal resistance, the alloys particle size of negative electrodes and the aluminum content inpositive electrodes were examined for the batteries during cycling. The results show that the cycling stability of the battery with the as-castalloy as negative electrode deteriorates due to the rapid pulverization and poor corrosion resistance of the alloy but could be improved afterannealing. Melt-spinning suppresses the pulverization and corrosion of the alloy and results in the prolonged cycle life of the batteries.

Abstract:系统研究了TiV2.1Nix(x=0.2,0.3,0.4,0.5,0.6)贮氢合金的相结构及电化学性能。XRD及SEM分析表明:合金均由体心立方(bcc)结构的V基固溶体主相和TiNi基第二相组成;随着Ni含量x的增加,合金中V基固溶体主相的相含量和晶胞参数逐渐减小,TiNi基第二相含量逐渐增多,且当x≥0.4时,TiNi基第二相组织沿主相晶界形成明显的三维网络状结构。电化学测试表明:随着x的增加,合金的高倍率放电性能及循环稳定性均得到显著改善;但当x从0.4增加到0.6时,合金的活化性能变差,最大放电容量降低。在研究的合金中,TiV2.1Ni0.4表现出较好的综合性能。

Abstract:采用低温燃烧合成工艺在甘氨酸-硝酸盐体系中制备出Ce0.8Nd0.2O1.9固溶体纳米粉末,重点考察了甘氨酸与硝酸盐的配比(G/N)以及焙烧温度对粉末特性的影响。通过热重-差示扫描量热分析(TG-DSC)得知,燃烧反应的点火温度为257℃。利用X射线衍射(XRD)、透射电镜(TEM)、比表面积仪(BET)及傅里叶红外光谱(FTIR)等手段对粉末的结构、形貌、成分、尺寸及比表面积进行了分析。结果表明:燃烧反应后直接得到萤石型结构的单相固溶体,晶粒尺寸为8nm~12nm之间,比表面积为38m2/g~47m2/g;晶粒尺寸随焙烧温度升高而增加,在800℃下焙烧1h后,可以去除反应残留物质,并使获得的晶形更加完整。

Abstract:采用直流磁控溅射法制备了Co1_(-x)Pt_x合金薄膜,并详细研究了其结构和磁学性能随x变化的规律。通过XRD结构分析可知:溅射态的薄膜当x≤28%时,为hcp结构;x=35%和40%时,为hcp和fcc的混合结构;x≥46%以后,为fcc结构。VSM测试结果表明:随x的增大,溅射态薄膜的矫顽力先增大后减小,当x=23%时,矫顽力达到最大值2147×79.6A/m,在x=46%处矫顽力急剧下降至100×79.6A/m左右,x>46%以后,矫顽力随x的增大不再明显变化。退火后,hcp结构的薄膜矫顽力基本不变,而接近等原子比的fcc结构的CoPt薄膜,由于部分转变为fct结构,矫顽力有很大提高;fcc结构的CoPt3薄膜矫顽力有所增大,但是增大不多。

Abstract:Anodizing process is an effective method to improve the surface properties of magnesium alloys. By now, much progress, including the optimization of electrolyte compositions, the selection of electric parameters, the film formation mechanism, the film structure and the post treatment, have been obtained based the traditional process, such as Dow 17 and HAE. In this paper, the details are reviewed and the trend of development is indicated.

Abstract:The investigations on the thermal physical properties of refractory metals (V, Nb, Ta, Mo, W et al) were reviewed in this paper. The interrelation between the thermal properties of the refractory metals and their microstructures were discussed from theoretical and experimental aspects. The study of the nanostructured refractory metals was mentioned. Finally the prospect for the research and application of the refractory metals was present.

Abstract:Technologic parameters of preparing nanocrystalline ITO(Indium Tin Oxide) powders by a hydroxide coprecipitation method were studied in this paper. The pH values of deposition beginning and its complete ending in the alkalescent solutions, and the pH values of dissolving beginning and its complete dissolving in the acidic solutions were computed, respectively, by using the equilibrium theory of thermodynamics. It is found that the pH values are functions of temperature. Thereout, the optimized designs of technologic parameters for manufacturing ITO powder have been made. HTEM, SEM, XRD have been used for measuring the nanosized ITO powders and found that the mean size is about 28 nm and grows along the crystal face (400).

Abstract:The mechanisms of the creep damage and the failure of the short fiber reinforced metal matrix composites (MMCs) have been investigated. The unit cell models are applied for the plane randomly-distributed-fiber MMCs by means of the finite element method (FEM) of ABAQUS. The creep damage and failure of the matrix is simulated by the K-R damage model, which has been implemented as the user subroutine CREEP of ABAQUS. The breakage of the fibers is simulated by the stress criterion, it means that the breakage will occur when the axial stress of the fibers reaches the critical value. This stress criterion has also been implemented into the ABAQUS. The influence of the fiber breakage on the stress distribution has been obtained. The FEM results show that the creep damage is localized near the corners of the fibers and the fractured surfaces of the fibers after the breakages of the fibers occur. And the fiber breakage has very limited influence on the creep damage of the matrix, but it reduces a high stress concentration in the matrix near the fractured surface. This high stress concentration will help the crack enlargement in the matrix by the stress criterions.

Abstract:通过对钛酸铅陶瓷气相扩渗稀土元素,制备了导电陶瓷材料. 通过X射线衍射、电子探针X射线能谱和扫描电镜测试分析,表明稀土元素La,Ce,Gd,Sm等均已渗入到PbTiO3陶瓷体相中,并生成了新的化合物La5O7NO3,La2C2O2,Gd2O3,La2Ti6O15,SmO和CeTi21O38,并使扩渗后的PbTiO3基陶瓷的导电性能发生了十分显著的变化,其室温电阻率从纯PbTiO3陶瓷的2.0×1010 (·m下降为0.2 (·m,而且随着温度的变化,晶粒电阻呈现明显的PTCR效应,而晶界电阻随着温度的升高,呈急剧连续降低状态,总电阻的变化规律与晶界电阻的变化相类似,试样总电阻的PTCR效应已不存在,已表现出导电体特征.

Abstract:采用直流磁控溅射法制备了Co1-xPtx合金薄膜,并详细研究了其结构和磁学性能随x变化的规律.通过XRD结构分析可知溅射态的薄膜当x≤28%时,为hcp结构;x=35%和40%时,为hcp和fcc的混合结构;x≥46%以后,为fcc结构.VSM测试结果表明随x的增大,溅射态薄膜的矫顽力先增大后减小,当x=23%时,矫顽力达到最大值2147×79.6 A/m,在x=46%处矫顽力急剧下降至100×79.6 A/m左右,x＞46%以后,矫顽力随x的增大不再明显变化.退火后,hcp结构的薄膜矫顽力基本不变,而接近等原子比的fcc结构的CoPt薄膜,由于部分转变为fct结构,矫顽力有很大提高;fcc结构的CoPt3薄膜矫顽力有所增大,但是增大不多.

Abstract:The isothermal section of Ni-Cr-Mo ternary system at 1358 K was determined by means of diffusion triple and electron microprobe analysis. The results indicate that one binary intermetallic of NiMo is formed in Ni-Cr-Mo ternary system at 1358 K. In this diffusion triple, Cr and Mo formed into a continuous solid solution, and Ni and (Cr,Mo) formed into a finite solid solution. No ternary compound was observed. One three-phase region of Ni+NiMo+(Cr, Mo) exixts in the isothermal section of Ni-Cr-Mo ternary system at 1358 K.

Abstract:采用高温固相反应法制备了Eu^3＋掺杂ZnO-MgO-La203-B203基质的光致发光光纤，通过轴向拉伸试验测量了该光纤的应力-应变曲线。应用弹脆塑性理论研究了屈服面的变化和应力-应变的本构关系，计算了拉伸弹性模量、拉伸强度、拉伸最大负荷、拉伸强度的应变、断裂伸长率和材料的脆性指数。结果表明，该光纤弹性模量高于普通玻璃和大理石，接近于硬铝合金和轧制铝，其拉伸强度和所能承载的负荷都较大。

Abstract:采用分子动力学法建立了熔体ZA27合金模型,并通过计算机模拟获得α相-熔体ZA27界面、α相- TiAl3化合物界面原子集团.用递归法计算了α相、TiAl3化合物的结构能,α相与熔体金属,α相与TiAl3化合物的界面能.计算结果表明：TiAl3化合物的结构能高于α相的结构能,合金凝固时TiAl3化合物先于α相从熔体中析出;α相与TiAl3化合物间的界面能低于α相与熔体金属间的界面能,α相以TiAl3化合物为基体形核比之从熔体金属直接形核增加的界面能少,可减少形核功,因此,TiAl3可成为α相的异质核心,增加α相形核率,细化合金组织.

Abstract:对用无压浸渗法制备的高含量Si/Al复合材料的浸渗及凝固组织进行了研究,对Si骨架间的凝固组织和浸渗过程中的水淬组织进行了详细的分析,并对2种组织进行了比较.结果表明,Si骨架间的过共晶Al-Si合金液的水淬组织为伪共晶组织,高速率的凝固阻碍了Si的析出和扩散.而在缓慢冷却凝固时,随着初晶Si的析出,形成呈网络状连续的Si相骨架,Si骨架间隙进一步减小,剩余的过共晶成分的液相被分隔局限其间,液相比例减少.在被Si相骨架分隔的微区内产生了类似于离异共晶的析出现象――初晶Si和共晶Si只能沿原预制体Si多孔体骨架上附着析出,凝固后的Al基体为α相,而不是典型的Al-Si共晶组织.另外,Si相的体积分数决定于浸渗温度.

Abstract:The microstructure, optical absorption properties and luminescence function of GaN thin films grown on the sapphire substrate with the buffer layer of GaN by MOCVD have been studied by means of XRD, TEM, infrared transmission spectrum, and photoluminescence. The XRD results show that the crystal of GaN is hexagonal wurtzite structure, The thin films have perferred orientation in c axis with very high quality. The TEM images of cross-sectional specimen show that the thicknesses of every layer in the superlattices are uniform with the average period of 13.3 nm, but there are high-density dislocations in the superlattices region. With the related optical experimental data, it had been found that the optical absorption edge was at about 370 nm. The theory calculation indicates that the five samples are direct transition semiconductor with band-gaps of about 3.4 eV. The refractive indexes of the samples increase with the photon energy enhance and decrease with the wavelength increasing. The results show that the extinction coefficients have the minimum at 370 nm. Photoluminescence test results show that the superlattice has preferable luminescence property and a yellow luminescence is found.

Abstract:采用熔渗/氮化复合处理技术对TiC-TiN基、WC基金属陶瓷进行了高温高压熔渗/氮化处理,通过扫描电镜、能谱仪、X射线衍射等分析技术对其显微组织、成分及结构进行了分析.结果表明：经过高温高压熔渗/氮化处理,WC-Co金属陶瓷未形成梯度结构;WC-TiC-Co金属陶瓷表面形成了TiN,但是从材料表面向内部的成分过渡存在明显的界面;TiC-TiN基金属陶瓷由表面到心部形成了梯度结构,其硬度自表面向心部呈现高-低-高的变化趋势, 该金属陶瓷表面主要形成了Ti（C0.3N0.7）.

Abstract:运用盐-金属反应法制备了亚微米TiB2颗粒增强铝基复合材料（TiB2/AC8A）.TiB2颗粒通过钛盐和硼盐与铝合金反应原位生成.对复合材料进行了显微组织观察和高温蠕变性能实验.原位TiB2颗粒的尺寸约为0.5μm,近似呈球形。TiB2／AC8A复合材料具有优异的高温蠕变性能。10ω／％TiB2原位颗粒（～0．5μm）增强AC8A复合材料的蠕变抗力比10φ／％SiCp（1．7μm）外加颗粒增强AI复合材料至少要高两个数最级。10ω／％TiB2／AC8A复合材料表现出高的名义应力指数（11．7～12．5）和名义激活能（265kJ／mol），其稳态蠕变数据能够用廊力指数为8的亚结构不变模型和门槛应力来解释。TiB2／AC8A复合材料的蠕变断裂行为符合Monkman-Grant关系式。

Abstract:采用高温熔炼方法后机械球磨和机械合金化方法分别制备了CoFe_3Sb_(12)和FeSb_2合金粉末,并对其电化学嵌锂性能进行了研究。研究发现,FeSb_2 的首次可逆容量为394 mAh·g-1,比CoFe_3Sb_(12) 的首次可逆容量(485 mAh·g-1)低。但是FeSb_2 容量衰减的速度要远远小于CoFe3Sb12。FeSb2 的容量保持率在第10 个循环时仍保持在70%以上,而CoFe_3Sb_(12 )却只有50%左右。通过二者嵌锂性能对比研究表明,减少嵌锂活性中心能有效地缓解合金类负极材料在循环中的容量衰减现象。

Abstract:利用溶胶-凝胶法制备了纳米晶La0.7Pb0.3FeO3气敏材料,并对其相组成、电导及其对CO气敏性能进行了研究.XRD结果表明：掺铅固溶体La0.7Pb0.3FeO3仍为正交晶系钙钛矿结构,粒径约为17nm,低于纯相LaFeO3的粒径31nm。电导测鼍显示：该材料足P型半导体导电行为，电导大于同温度下纯相LaFeO3的电导，且电导突变温度有所降低。气敏性能研究表明：Pb掺杂对其CO气敏性能有了明显改善。

Abstract:为计及强散射偶极子间的相互作用,引入参量εh和μh,利用广义多重散射理论及MATLAB计算机软件对在2 GHz～18 GHz频率下的体积占空比为8%的铁纤维随机混合媒质等效磁导率的实验值进行曲线的拟合,导出了耦合系数εh和μh,并在此基础上,对体积占空比分别为30%和20%的铁纤维随机混合媒质等效磁导率进行了计算,计算结果与实验吻合良好.

Abstract:在950℃的氮化温度下,通过单氢氧化镓（GaO2H）粉末与流动的NH3反应35 min制备出粒状GaN微晶.通过X射线衍射（XRD）和扫描电镜（SEM）研究发现,GaN粉末是六角纤锌矿结构的粒状微晶,其晶格常数a和c分别为0.3191 nm和0.5192 nm.X射线光电子能谱（XPS）揭示试样中有Ga-N键形成,Ga与N两元素比为1∶1.

Abstract:Pure Ni nanopowders were successfully prepared by the anodic arc discharged plasma method with homemade experimental apparatus. The nanoparticles by this process were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), selected area electron diffraction (SAED), and BET adsorption to determine the chemical composition, morphology, crystal structure, specific surface area, particle size and particle size distribution. Element analyze instrument is also used to determine the C, H, N contents. The main constituent elements were examined by energy dispersive X-ray spectroscopy (EDS) equipped in SEM and the structure compose was qualitatively analyzed by FT-IR spectrum. The experimental results showed that the crystal structure of samples was fcc structure same as the bulk material with an average grain size of about 47 nm, ranging from 20 nm to 70 nm. The sample has high purity and strong adsorption, whose particles distributed uniformly in spherical chain shape with a specific surface area of 14.23 m2/g.

Abstract:It is important by in-situ synthesis method to fabricate magnesium matrix composites. In-situ synthesis of magnesium matrix composites reinforced with TiC ceramics by remelting and diluting method was studied in the paper. It was found through microstructure observation and XDR analysis that the fine reinforcements dispersed uniformly in magnesium matrix composites. It was indicated that the damping capacity of magnesium matrix composites was less than that of pure magnesium due to the addition of TiC, but the damping capacity of magnesium matrix composites can be enhanced by heat treatment.

Abstract:采用液相压力浸渍工艺制备出碳化硅颗粒(SiCp)和硅酸铝短纤维(Al2O3·SiO2f)混杂增强的镁基复合材料,研究了其机械与阻尼性能。发现镁基复合材料的强度与纯镁相比得到了显著的改善,而阻尼性能有所降低。并且2个弛豫内耗峰存在于复合材料试样中,出现在约150℃的峰Ⅰ不仅存在于纯镁试样中而且还存在于其复合材料试样中,认为其与位错的运动有关;出现在约250℃的峰Ⅱ仅存在于复合材料的试样中,分析认为是由于碳化硅颗粒与镁基体的界面滑移所致。

Abstract:通过液态原位反应合成制备MgO/Mg2Si增强Mg-Li基复合材料,利用TEM对增强相形态及界面结构进行了观察.实验结果表明,复合材料中增强粒子与基体界面结合良好,无反应物生成.确定了增强粒子与基体的界面取向关系,MgO与基体α相的晶体学关系为[100]MgO//[40（￣4）3]α,（011）MgO//（（￣1）2（￣1）0）α;Mg2Si与基体β相的晶体学关系为[310]Mg2Si//[411]β,（1（￣3）（￣1））Mg2Si//（001）β.

Abstract:Morphological evolutions and kinetics process controlled by transformation-induced elastic strain (include external strain field) during isostructure phase separation are systematically investigated using prototype binary alloy by diffuse-interface field model. The results show that various types of morphologies, such as basket-weave structures, sandwich-like multi-domain structures, precipitate macro lattices and plate-like structures, are predicted in different stages of phase separation. It is demonstrated that the precipitates are preferentially oriented with an external stress for an inhomogeneous elastic modulus system. Moreover, the simulation results also indicate that the small particles will be connected along elastic soft directions to formation bigger particles in the stage of growth and those small isolated particles will be consumed by bigger particles in the stage of ripening.

Abstract:通过调整合金的组成,优化其熔炼和热处理过程,制备出一种新组成的富La贮氢合金La0.62Ce0.25Pr0.03Nd0.10Ni3.69Co0.71Mn0.34Al0.29Zr0.005,用扫描电镜、压力-恒温实验、X射线衍射、恒电流充放电和循环伏安扫描方法对合金进行了表征.结果表明：该合金为六方晶系的CaCu5型结构;高温下氢的吸脱附平台低,65℃时压力平台为0.1MPa：初始容量高达335mAh／g，2C经500次循环后，容降仅为18．6％．

Abstract:Nanocrystalline CuCr alloys with a relative density of above 98% can be prepared by high energy ball milling and hot pressing technique. The grain size of nanocrystalline CuCr alloy is less than 50 nm. The vacuum arc instability and chopping current of nanocrystalline CuCr materials were studied in an artificial circuit. The results show that the vacuum arc of nanocrystalline CuCr is more stable than that of conventional materials, the chopping current is 17%-35 % of that of conventional alloys.

Abstract:将高能球磨后的Ti-Al粉末和TiC,Al2O3粉末混合进行热压烧结,在烧结的过程中反应生成金属间化合物为增强相的复合材料.通过对粉料的X射线衍射分析、热分析（DSC）和烧结体的成分分析表明,最终的金属间化合物只有Ti3Al而没有其它金属间化合物相.通过热力学计算,分析了反应烧结过程并发现在低温由固相间原子扩散控制生成TiAl3,TiAl,Ti3Al的渐进过程,和在高温下金属间化合物的合成机理,而且增强相和基体界面间处于稳定状态.

Abstract:研究了化学计量比对AB4.8~AB5.2贮氢合金电化学性能的影响。结果表明:在本实验研究范围内,当x=0.1时,贮氢合金电极的0.2C,1C和5C放电容量、高倍率放电特性及3C循环寿命分别达到324mAh·g-1,301mAh·g-1,263mAh·g-1,0.81和530次。此外,化学计量比对贮氢合金的活化性能和温度特性均有较大的影响,当x分别为–0.2,–0.1,0.0,0.1和0.2时,贮氢合金电极在0.2C充放电的条件下活化次数分别为3次、4次、7次、5次和6次,且随着x的增大,贮氢电极的高温(45℃,1C)和常温(25℃,1C)放电效率下降,低温(–18℃,1C)放电效率则有增大的趋势。从合金活化性能、大电流充放电特性和循环稳定性来看,x=0.1时(AB5.1),能得到具有较佳的电化学性能的贮氢材料。

Abstract:用直流反应磁控溅射法制备了TiO2薄膜,并对热处理前后试样的紫外可见光谱（UV-Vis spectrum）和荧光发射光谱（PL Spectrunm）做了研究。发现热处理后试样的紫外可见光谱在496nm处出现了一个较为明显的吸收峰，荧光发射光谱496．5nm处出现一个荧光发射带肩。X射线光电予能谱（XPS）的分析结果表明，热处理可使薄膜中晶格氧扩散出去，生成Ti^3＋离子和氧空位。结合XPS的分析结果和理论计算，可推断热处理后出现的位于496nm处的吸收峰和496．5nm处的荧光带肩可被指认为薄膜中Ti^3＋离子的d电子跃迁产生。

Abstract:The micro-arc oxidization is an efficient and pollution-free technique of surface processing and can form in situ a ceramic layer on the surface of nonferrous metal. In this paper, the micro-arc oxidization ceramic layer was formed on the surface of TiAl alloy by using a self-designing pulse power supply equipment of micro-arc oxidization. The oxidation dynamics of the ceramic layer on the surface of TiAl alloy was studied in the cycle high temperature condition and the experimental results show that the oxidation dynamics curve of TiAl alloy micro-arc oxidization ceramic layer submitted a parabolic function, which indicates that the ceramic layer can protect the TiAl alloy. Moreover, the effect of SiO3^2- on the characteristics of the ceramic layer was also studied, the results show that the working temperature with a micro-arc oxidization ceramic layer can be increased to 1273 K after adding SiO3^2- in the solution of the micro-arc oxidization. Analyzing by SEM and XRD test, the TiAl alloy ceramic layer contained 80 percent Al2TiO5, 11 percent TiO2 and 9 percent SiO2, which indicates that the addition of SiO2 can effectively restrain the decomposition of Al2TiO5 at high temperature and thus significantly increase the anti-oxidation of the TiAl alloy.

Abstract:通过冷变形拉拔并结合中间热处理制备了纤维相增强的Cu-12%Ag合金线材.通过不同温度下退火不同时间,研究了等温过程对Cu-12%Ag合金组织性能的影响.200℃等温退火时强化相仍能基本保持纤维形态,强度略有下降,电导率略有上升.300℃等温退火时纤维相界面局部迁移,退火初期合金电导率较快上升而强度较快下降,随后电导率上升或强度下降速率变缓.400℃等温退火时组织发生明显再结晶和晶粒粗化,退火初期合金电导率剧烈上升而强度剧烈下降,随时间延长,强度下降趋势变缓而电导率达到最高值后略有下降.可以用纤维组织的回复、再结晶、次生相析出及溶质原子溶解等因素在等温退火过程中的变化来分析材料组织、性能的变化.

Abstract:Tow kinds of Mo-N alloyed Iayers were fabricated on the surface of Ti6Al4V alloy by Xu-Tec process. One process was Mo-diffusing with nitriding simultaneously,and the other is nitriding after Mo-diffusing. This paper investigated their friction and wear behaviors against a polished 2100 steel counterbody ball under ball-on-disc test condition.It has been found that both the two Mo-N diffusion layers have excellent wear-resistant hehavior in sliding hut their friction coefficient increases slightly.The war rate for Mo-diffusing with simullaneous nitriding 400 times less than Ti6Al4V and 1080 times less for nitriding after Mo-diffusing.

Abstract:采用SiC/Si3N4陶瓷先驱体聚硅氮烷连接反应烧结碳化硅陶瓷,研究了连接温度、连接压力、浸渍/裂解增强处理对连接强度的影响.结果表明：在1100℃～1400℃温度范围内,连接强度先升高后降低;连接过程中施加适当的轴向压力可提高连接层致密度;浸渍/裂解增强处理可大幅度提高接头强度.当连接温度为1300℃,连接压力为15kPa，经3次增强处理的连接件抗弯强度达最大值169．1MPa。这种连接件的断口表面粘有大量SiC母材。由XRD研究表明，随着温度的逐步升高，聚硅氮烷的裂解产物发生了由非晶态向晶态的转变。微观结构及成分分析显示：连接层为厚度2μm-3μm的SiCN无定形陶瓷，其结构较为均匀致密；连接层与基体间界面接合良好。

Abstract:研究了采用悬浮熔炼（常规铸态）和不同冷却速度的单辊快淬方法制备的Mm（NiCoMnAl）5型稀土系贮氢合金负极活性材料对金属氢化物镍（MH/Ni）电池性能的影响.结果表明,采用不同方法制备的合金对整个电池活化后的容量和内阻影响很小,但是常规铸态合金在退火后降低了电池的放电电压平台,快淬合金随着冷凝速率的提高,放电平台呈降低趋势.对循环充放电过程中电池内阻、循环到一定次数时负极贮氢合金的粒度和正极内铝含量的测试结果表明,铸态不退火合金较差的抗粉化性和较差的耐腐蚀性使电池的循环性能较差,经退火后其性能均有所提高,快淬合金使电池的循环性能优于常规铸态合金.

Abstract:利用超临界CO2流体、溶剂和热处理3种方法对ZrO2陶瓷注射成型坯体进行脱脂,并对试样进行了一系列的性能测试.实验结果显示,脱脂方法对陶瓷性能有较大的影响.超临界流体脱脂克服了热脱脂的开裂、变形等各种缺陷,使烧结件获得较好的力学性能,平均抗弯强度σ为1074MPa，Weibull模数m达到18．93，高于利用溶剂脱脂的烧结件（σ=1038．4MPa，m=13．28）和热脱脂烧结件（σ=983．5MPa，m=7．59）。此外，超临界CO2流体脱脂、溶剂脱脂可使陶瓷注射成型脱脂时间大大减少，脱脂过程约缩短到热脱脂的1／20。

Abstract:采用纯度分别为99.94%和99.2%的稀土金属Gd,配制了Gd5Si1.9Ge2.1和Gd5Si1.72Ge2.28两组合金,研究杂质对Gd5（SixGe1-x）4合金磁熵变的影响原因。粉末衍射结构分析表明，所研究的合金中都有Gd5Si2Ge2相，而采用低纯Gd配制的Gd5（SixGe1-x）4合金中还出现了明显的Gd5（Si，Ge）3相。磁性测量表明，杂质不改变合金中主相的居里温度，即没有改变合金中主相磁性原了的相互作用，但由于低温反铁磁性Gd5（Si，Ge）3相对室温Gd5Si2Ge2相的磁熵变没有贡献，导致Gd5（Si，Ge1-x）4合金在室温附近的磁熵变下降。

Abstract:采用中性盐雾、周期浸润等人工加速腐蚀试验和电化学测试方法,研究了Al-6Mg-Zr和Al-6Mg-Zr-Sc 2种铝合金在模拟海水环境中的腐蚀行为.结果发现：在试验环境中2种铝合金都发生了点蚀;添加了Sc元素的Al-6Mg-Zr-Sc合金比Al-6Mg-Zr合金表现出更好的耐蚀性.自腐蚀电位和动电位阳极极化曲线研究也发现,添加Sc元素后铝合金的耐蚀性能增强.SEM/EDX分析表明,Al-6Mg-Zr-Sc合金中存在的Al3（Sc, Zr）复合相能细化晶粒、有效地抑制Al-6Mg-Zr合金中β相（Mg5Al8）的析出,使β相在合金基体中呈不连续分布,从而降低了合金的腐蚀敏感性.

Abstract:To obtain a better bioactive apatite coating, a brushite coating on the carbon/carbon composite prepared by sonoelectrodeposition technique was treated for 1 hour in an alkaline solution. The morphologies, structures and compositions of the calcium phosphate coatings were analyzed with SEM, XRD, FTIR and EDAX, and the bonding strength of coatings was also measured. The results show that the difference in the morphologies of the calcium phosphate coatings is no significant before and after the alkaline-heat treatment, however, a more compact coating can be obtained after the alkaline-heat treatment. The vertical distributions of different elements such as P, O, Ca and C were found between the coating and substrate. The bonding strength is more than 3 MPa, maximum to 4.2 MPa. Failure of the coating mainly occurred inside the coating due to the cohesive breakage of apatite coating.

Abstract:In the present work, the principles and processing modes of equal channel angular pressing (ECAP) for as-cast magnesium alloys were investigated. With structural design of ECAP die, the accumulated effect of shear strains under ECAP was calculated. By observation of optical microstructure of single-passed ECAP deformed cast ingot of AM60 magnesium, the effective relationship of die geometric structure (angle and subtending one at corner between entry and exit channels) to the evolution of deformed microstructure was discussed. Based on the curves of displacement versus extrusion force during multi-passed ECAP, a mode of evolution of deformed microstructure was analyzed under different pressing conditions (e.g. number of passes, back-forces, and deforming rate). Routine of experiment and modeling for ECAP of magnesium alloys was schemed. It can be concluded from the study that the ECAP deformed microstructure of AM60 casting ingot fits the one estimated by theory of plastic mechanics well. Multi-passed ECAP can perfect the microstructure of alloy tremendously. For as-cast magnesium alloys characterized by coarse-grained structure, ECAP is an effective thermo-mechanical processing to make their ultra-fine grains.

Abstract:研究了包套锻造对大尺寸高铌TiAl合金室温塑性的影响.结果表明,经过多步包套锻造后,合金室温塑性大大改善,延伸率可达2.29%.这主要归于：多步包套锻造有效地破碎了粗大的铸态组织以及在锻造过程发生了动态再结晶,这样不仅使合金平均晶粒尺寸降低,而且使合金晶粒分布均匀化,得到均匀细小的双态组织.此外,高铌TiAl合金经多步锻造后,有效消除了晶界偏析的脆性β相,从而使合金的室温塑性得到改善.

Abstract:系统研究了TiV2.1Nix（x=0．2，0．3，0．4，0．5，0．6）贮氢合金的相结构及电化学性能。XRD及SEM分析表明：合金均由体心立方（bcc）结构的V基固溶体主相和TiNi基第二相组成；随着Ni含量x的增加，合金中V基固溶体主相的相含量和品胞参数逐渐减小，TiNi基第二相含量逐渐增多，且当x≥0．4时，TiNi基第二相组织沿主相晶界形成明显的三维网络状结构。电化学测试表明：随着x的增加，合金的高倍率放电性能及循环稳定性均得到显著改善；但当x从0．4增加到0．6时，合金的活化性能变差，最大放电容量降低。在研究的合金中，TiV2.1Ni0.4表现出较好的综合性能。

Abstract:采用低温燃烧合成工艺在甘氨酸-硝酸盐体系中制备出Ce0.8Nd0.2O1.9固溶体纳米粉末,重点考察了甘氨酸与硝酸盐的配比（G/N）以及焙烧温度对粉末特性的影响.通过热重-差示扫描量热分析（TG-DSC）得知,燃烧反应的点火温度为257℃.利用X射线衍射（XRD）、透射电镜（TEM）、比表面积仪（BET）及傅里叶红外光谱（FTIR）等手段对粉末的结构、形貌、成分、尺寸及比表面积进行了分析.结果表明：燃烧反应后直接得到萤石型结构的单相固溶体,晶粒尺寸为8nm-12nm之间，比表向积为38m^2/g～47m^2／g；晶粒尺寸随焙烧温度升高而增加，在800℃下焙烧1h后，可以去除反应残留物质，并使获得的品形更加完整。

Abstract:采用磁控溅射方法制备FePt（50nm）和[FePt（2nm，3nm，5nm）／C（1nm）]。膜，并在550℃退火30min，研究了周期数（n）对FePt／C系列多层膜结构及磁学性能的影响。结果表明：退火后多层膜的矫顽力在总膜层厚度约为30nm时出现最大值；随着n的增大，多层膜的饱和磁化强度和晶粒尺寸均不断增大；C的加入可以有效降低晶粒间交换耦合作用。刚此可以通过控制周期数得到县仃合适的微观结构和高的磁学性能的FePt／C多层膜，从而满足超高密度磁记录介质的要求。