SPS法制备的赝二元合金（Ga2Te3）x-（Bi0．5Sb1．5Te3）1-x（x=0～0．2）电学性能

采用放电等离子烧结（SPS）方法制备了赝二元合金（Ga2Te3）（Bi0.5Sb1.5Te3）1-x（x=0—0．2），并研究其电学性能。结果表明，在318K时（Ga2Te3）x-（Bi0.5Sb1.5Te3）1-x（x=0．1）合金的电导率为3．7×10^4Ω^-1·m^-1，是三元合金Bi0.5Sb1.5Te3的2倍，而Seebeck系数没有明显下降。从所测得的a和σ值可知，赝二元（Ga2Te3）x-（Bi0.5Sb1.5Te3）1-x（x=0．1）合金的功率因子最大，为2．1×10^-3（W·K^-2·m^-1），是三元Bi0.5Sb1.5Te3合金的1．5倍。     

Ca1-3xLn2xTiO3（x=0．13，0．2；Ln=La，Nd，Sm）高介微波介质陶瓷

探讨了烧结温度、组成和稀土元素对Ca1-3xLn2xTiO3（x=0．13，0．2；Ln=La，Nd，Sm）陶瓷的晶体结构、微波介电性能的影响。X射线衍射（XRD）分析表明，除Ca1-3xLn2xTiO3（x=0．2；Ln=Sm）陶瓷中含有少量的第二相（Sm2Ti2O7）外，其余Ca1-3xLn2xTiO3（x=0．13，0．2；Ln=La，Nd，Sm）陶瓷均形成了单一正交钙钛矿相。x=0．13的样品微波介电性能明显优于相应的x=0．2的样品。部分Ca1-3xLn2xTiO3（x=0．13，0．2；Ln=La，Nd，Sm）陶瓷微波介电性能如下：ε=119．6、Qf=10674GHz、τf=304．4×10^-6/℃（x=0．13、Ln=La）；ε=108．9、Qf=14919GHz、τf=236．2×10^-6／℃（x=0．13、Ln=Nd）；ε=101．3、Qf=14485GHz、τf=186．6×10^-6／℃（x=0．13、Ln=Sm）。     

12CAO·7Al2O3和γ-2CaO·SiO2混合物相的合成和溶出性能研究

本文研究了CaO的加入量、合成温度、保温时间和出炉温度对合成产物物相的影响,结果发现：当CaO2Al2O3：SiO2为2．38：1：0．77,合成温度1500℃,保温时间30min和出炉温度100℃时可获得只含有12CAO·7Al2O3和γ-2CaO·SiO2且氧化铝溶出性能较好的物料。采用二次回归正交试验法对读物料进行了溶出性能的研究,详细考察了其受碳钠浓度、氧化铝浓度、溶出温度、溶出时间和液固比的影响规律,得到的回归方程在0．01水平上高度显著,且方程回归值与试验值的相对误差不超过3％,回归方程的教学表迭式为：氧化铝溶出率Y=-3．094×100Nc^2-4．049×10^-5fT＋5．853×10^-3Nc＋3．192×10^-3t＋4．888×10^-3T＋5．183×10^-2L／S-5．99×10^-3．     

涂层对Si02／（Si3N4＋BN）透波材料力学、介电性能的影响

采用硅树脂作为SiO2／（Si3N4＋BN）复合材料涂层，并取得较好的防潮效果。将SiO2／（Si3N4＋BN）复合材料涂层后弯曲强度提高约27％左右；介电常数和介电损耗角正切变化分别为0．02和0．2×10^-3。     

铬基合金连接体材料在固体氧化物燃料电池中的应用

主要介绍了固体氧化物燃料电池（SOFC）的铬（Cr）基合金连接体材料的发展现状。Cr基合金具有良好的抗氧化性、耐腐蚀性和导电性能等，是目前连接体材料中的研究热点之一。在SOFC阴极环境中，容易形成氧化层，同时由于Cr的扩散和挥发还可能导致阴极中毒，合金中掺杂稀土元素（Y、La、Ce和Zr）可以抑制Cr2O3层的生成。在阳极环境中，Cr基合金的表现优于阴极。与Al2O3、NiO、MgO和TiO2等相比，Cr2O3基氧化层具有较好的综合性能，其耐高温（1100℃）、热膨胀系数（9．6×10^-6K^-1）和YSZ电解质（10．8×10^6K^-1）相近、且具有较好的导电性。目前，Cr基合金的研究重点是氧化物弥散强化（ODS）合金，使用最多的是Cr5FelY2O3，其热膨胀系数为9×10^-6K^-1～10×10^-6K^-1（1000 ℃），抗氧化性能较好。     

利用可控In气氛下热处理工艺制备Cd0．9Zn0．1Te：In

利用控制In气氛下的热处理工艺成功地制备了CdZnTe：In。不同In压下（Cd，Zn分压保持在平衡分压）的热处理实验结果表明：热处理后样品的电阻率可从6．75×10^5Ω·cm提高到10^8～10^1010Ω·cm；并且随着In压的增加，导电类型逐渐由p型转变为n型。热处理后样品的电阻率变化特征可以由In的扩散和施主缺陷InCd、受主缺陷VCd之间的补偿作用来很好地解释。利用扩散理论建立了CdZnTe：In的电阻率物理模型。利用热处理后样品的电阻率数据，计算了在873，973和1073K时In原子在CZT晶体中的有效扩散系数DIn，分别为3．455×10^-11，2．625×10^-10和5．17×10^-9cm^2／s。将扩散数据经过拟合后得到了DIn的表达式：1．35exp（-1．85eV／kT）cm^2／s（873～1073K）。     

低介低温烧结玻璃／钙长石复合绝缘材料的研究

通过对低介电常数 CaO-Li2O-B2O3-SiO2-Al2O3玻璃设计及与钙长石晶体的复合优化，制备了具有低温、低介、与硅相匹配的低热膨胀系数的新型绝缘复合材料。样品在970℃烧结0．5h后，介电常数5．125，介质损耗2．48×10^-3，抗折强度105．8MPa，热膨胀系数（25～500℃）3．38×10^-6℃^-1。并研究了玻璃与钙长石加入量、显微结构等因素对材料性能的影响。     

Ti-15-3钛合金应变速率循环超塑性研究

应变速率循环法是一种新式的超塑性实验方法，即试样在拉伸变形过程中，应变速率的大小按预定规律连续β循环变化，直至试样拉断，从而获得材料超塑性力学性能参数。采用这种方法研究Ti-15V．3Cr-3Sn-3Al（简称Ti-15-3）合金的超塑性。实验用原材料选自区轧制的板材，未经细化处理，晶粒平均尺寸为100μm。结果表明，该合金具有良好的超塑性，在应变速率范围3．2×10^-4～3．2×10^-5／s内，最佳变形温度为900℃，伸长率为621％。超塑性变形的机制是晶界滑动为主，晶内变形和位错蠕变起协调作用。     

真空熔炼AZ91镁合金过程中Mg元素的蒸发行为

在真空Ar气氛中熔炼AZ91镁合金，测定了不同精炼温度下Mg元素的蒸发速率。结果表明，随着精炼温度的升高，Mg元素的蒸发量增大。通过计算可知，Mg的蒸气压是Al的10^9倍，是Zn的46倍，因此主要是Mg的蒸发而导致合金其他元素含量升高。XRD分析表明，蒸发物是Mg元素。结合Mg元素的蒸发机制，在该试验条件下推导出Mg元素蒸发率的计算公式以及Mg元素的表观传质系数、蒸发率与精炼温度的关系，计算得出Mg元素蒸发率为0．86×10^-3-1．35×10^3g／cm^2·s，Mg元素的表观传质系数在2×10^-5-24×10^-5cm／s范围内。     

添加CeO2对BZN和BMZN微波陶瓷介电性能的影响

添加CeO2对BZN和BMZN微波陶瓷介电性能的影响表明，引入CeO2对BZN和BMZN陶瓷密度和微观形貌没有明显的影响，也不易造成第二相的形成；添加适量的CeO2能调节BZN和BMZN陶瓷的谐振频率温度系数在-10^-5／℃～＋10^-5／℃之间；CeO2对BZN陶瓷Qf值的影响不大，但会使BMZN陶瓷的Qf值明显降低；考虑电容率、Qf值和谐振频率温度系数三方面因素，获得较好性能的BZN和BMZN陶瓷性能如下：BZN＋0．75％CeO2，εr=39．45，Qf=51201GHz，τf=8．20×10^-6／℃：BMZN＋0．50％CeO2，εr=40．48，Qf=51381GHz，τf=12．7×10^-6／℃。     

Effects of Post-weld Heat Treatment on Microstructure,Mechanical Properties and the Role of Weld Reinforcement in 2219 Aluminum Alloy TIG-Welded Joints

In as-welded state, each region of 2219 aluminum alloy TIG-welded joint shows diff erent microstructure and microhardness due to the diff erent welding heat cycles and the resulting evolution of second phases. After the post-weld heat treatment, both the amount and the size of the eutectic structure or θ phases decreased. Correspondingly, both the Cu content in α-Al matrix and the microhardness increased to a similar level in each region of the joint, and the tensile strength of the entire joint was greatly improved. Post-weld heat treatment played the role of solid solution strengthening and aging strengthening. After the post-weld heat treatment, the weld performance became similar to other regions, but weld reinforcements lost their reinforcing eff ect on the weld and their existence was more of an adverse eff ect. The joint without weld reinforcements after the post-weld heat treatment had the optimal tensile properties, and the specimens randomly crack in the weld zone.     

The First Phase of the SRIF Industrialized Base in ＂West Area＂ Has Been Put into Operation

After nearly two years＇ tense construction, the first phase of industrialized base of Shenyang Research Institute of Foundry （SRIF）, located at the Tiexi Casting and Forging Industrial Park in the west of Tiexi District, has now been completed and formally put into operation.     

Thermodynamics Study on the Decomposition of Chromite with KOH

Institute of Process Engineering, Chinese Academy of Sciences, China, has proposed a method for oxidative leaching of chromite with potassium hydroxide. Understanding the mechanism of chromite decomposition, especially in the potassium hydroxide fusion, is important for the optimization of the operating parameters of the oxidative leaching process. A traditional thermodynamic method is proposed and the thermal decomposition and the reaction decomposition during the oxidative leaching of chromite with KOH and oxygen is discussed, which suggests that chromite is mainly destroyed by reactions with KOH and oxygen. Meanwhile, equilibrium of the main reactions of the above process was calculated at different temperatures and oxygen partial pressures. The stable zones of productions, namely, K2CrO4 and Fe2O3, increase with the decrease of temperature, which indicates that higher temperature is not beneficial to thermodynamic reactions. In addition, a comparison of the general alkali methods is carried out, and it is concluded that the KOH leaching process is thermodynamically superior to the conventional chromate production process.     

Influence of Heat Treatment on Damping Behaviour of the Magnesium Wrought Alloy AZ61

The effect of isochronal heat treatments for 1h on variation of damping, hardness and microstructural change of the magnesium wrought alloy AZ61 was investigated. Damping and hardness behaviour could be attributed to the evolution of precipitation process. The influence of precipitation on damping behaviour was explained in the framework of the dislocation string model of Granato and Lücke.     

Effect of Rare Earth Doping on Impedance,Modulus and Conductivity Properties of Multiferroic Composites:0.5(BiLa_xFe_(1-x)O_3)–0.5(PbTiO_3)

The Lanthanum-doped bismuth ferrite–lead titanate compositions of 0.5(Bi LaxFe1-xO3)–0.5(Pb Ti O3)(x = 0.05,0.10,0.15,0.20)(BLxF1-x-PT) were prepared by mixed oxide method.Structural characterization was performed by X-ray diffraction and shows a tetragonal structure at room temperature.The lattice parameter c/a ratio decreases with increasing of La(x = 0.05–0.20) concentration of the composites.The effect of charge carrier/ion hopping mechanism,conductivity,relaxation process and impedance parameters was studied using an impedance analyzer in a wide frequency range(102–106Hz) at different temperatures.The nature of Nyquist plot confirms the presence of bulk effects only,and non-Debye type of relaxation processes occurs in the composites.The electrical modulus exhibits an important role of the hopping mechanism in the electrical transport process of the materials.The ac conductivity and dc conductivity of the materials were studied,and the activation energy found to be 0.81,0.77,0.76 and 0.74 e V for all compositions of x = 0.05–0.20 at different temperatures(200–300 °C).     

Quantitative Analysis of the Crystallographic Orientation Relationship Between the Martensite and Austenite in Quenching–Partitioning–Tempering Steels

The orientation relationships(ORs)between the martensite and the retained austenite in low-and medium-carbon steels after quenching–partitioning–tempering process were studied in this work.The ORs in the studied steels are identified by selected-area electron diffraction(SAED)as either K–S or N–W ORs.Meanwhile,the ORs were also studied based on numerical fitting of electron backscatter diffraction data method suggested by Miyamoto.The simulated K–S and N–W ORs in the low-index directions generally do not well coincide with the experimental pole figure,which may be attributed to both the orientation spread from the ideal variant orientations and high symmetry of the low-index directions.However,the simulated results coincide well with experimental pole figures in the high-index directions{123}_(bcc).A modified method with simplicity based on Miyamoto’s work was proposed.The results indicate that the ORs determined by modified method are similar to those determined by Miyamoto’method,that is,the OR is near K–S OR for the low-carbon Q–P–T steel,and with the increase of carbon content,the OR is closer to N–W OR in medium-carbon Q–P–T steel.     

Using Finite Element and Contour Method to Evaluate Residual Stress in Thick Ti-6Al-4V Alloy Welded by Electron Beam Welding

This work was to reveal the residual stress profile in electron beam welded Ti-6Al-4V alloy plates(50 mm thick) by using finite element and contour measurement methods.A three-dimensional finite element model of 50-mmthick titanium component was proposed,in which a column–cone combined heat source model was used to simulate the temperature field and a thermo-elastic–plastic model to analyze residual stress in a weld joint based on ABAQUS software.Considering the uncertainty of welding simulation,the computation was calibrated by experimental data of contour measurement method.Both test and simulated results show that residual stresses on the surface and inside the weld zone are significantly different and present a narrow and large gradient feature in the weld joint.The peak tensile stress exceeds the yield strength of base materials inside weld,which are distinctly different from residual stress of the thin Ti-6Al-4V alloy plates presented in references before.     

Microstructures and Tensile Properties of Ultrafine-Grained Ni–(1–3.5) wt% SiC_(NP) Composites Prepared by a Powder Metallurgy Route

Silicon carbide nanoparticle-reinforced nickel-based composites(Ni–Si CNP),with a Si CNPcontent ranged from1 to 3.5 wt%,were prepared using mechanical alloying and spark plasma sintering.In addition,unreinforced pure nickel samples were also prepared for comparative purposes.To characterize the microstructural properties of both the unreinforced pure nickel and the Ni–Si CNPcomposites transmission electron microscopy(TEM) was used,while their mechanical behavior was investigated using the Vickers pyramid method for hardness measurements and a universal tensile testing machine for tensile tests.TEM results showed an array of dislocation lines decorated in the sintered pure nickel sample,whereas,for the Ni–Si CNPcomposites,the presence of nano-dispersed Si CNPand twinning crystals was observed.These homogeneously distributed Si CNPwere found located either within the matrix,between twins or on grain boundaries.For the Ni–Si CNPcomposites,coerced coarsening of the Si CNPassembly occurred with increasing Si CNPcontent.Furthermore,the grain sizes of the Ni–Si CNPcomposites were much finer than that of the unreinforced pure nickel,which was considered to be due to the composite ball milling process.In all cases,the Ni–Si CNPcomposites showed higher strengths and hardness values than the unreinforced pure nickel,likely due to a combination of dispersion strengthening(Orowan effects) and particle strengthening(Hall–Petch effects).For the Ni–Si CNPcomposites,the strength increased initially and then decreased as a function of Si CNPcontent,whereas their elongation percentages decreased linearly.Compared to all materials tested,the Ni–Si CNPcomposite containing 1.5% Si C was found more superior considering both their strength and plastic properties.     

Directional Growth of Tin Crystals Controlled by Combined Solute Concentration Gradient Field and Static Magnetic Field

A new method was introduced to achieve directional growth of Sn crystals. Microstructures in liquid(Pb)/liquid(Sn) diffusion couples were investigated under various static magnetic fields. Results show that the β-Sn crystals mainly reveal an irregular dendritic morphology without or with a relatively low static magnetic field(B0.3 T). When the magnetic field is increased to 0.5 T, the β-Sn dendrites close to the final stage of growth begin to show some directional character. With a further increase in the magnetic field to a higher level(0.8–5 T), the β-Sn dendrites have an enhanced directional growth character, but the dendrites show a certain deflection. As the magnetic field is increased to 12 T, the directional growth of the β-Sn dendrites in the center of the couple is severely destroyed. The mechanism of the directional growth of the β-Sn crystals and the deflection of the β-Sn crystals with the application of static magnetic field was tentatively discussed.     

电化学噪声数据处理方法概述

综述了常见的电化学噪声数据处理方法,介绍了直流趋势剔除、统计分析、快速傅立叶变换(FFT)法计算功率谱密度(PSD)以及小波变换处理电化学噪声信号的基本过程,并阐释了各种数学处理及所得参数的物理意义。