有无个磁场下铁在H2SO4＋K2Cr2O7溶液中的电化学状态和阴极化行为

在［Ｈ２ＳＯ４］为０．１－２ｍｏｌ／Ｌ、［Ｋ２Ｃｒ２Ｏ７］为０．０１＝０．４ｍｏｌ／Ｌ的范围内，研究了Ｆｅ／Ｈ２ＳＯ４＋Ｋ２Ｃｒ２Ｏ７系统的电化学状态和阴极极化行为，讨论了［Ｈ２ＳＯ４］、［Ｋ２Ｃｒ２Ｏ７］和［Ｈ２ＳＯ４］／［Ｋ２Ｃｒ２Ｏ７］比值与Ｆｅ的电化学状态的关系。分析了所出现的五种类型阴极极化曲线和外磁场对阴极过程的影响。     

Rh（III）—5—Br—PADAP配合物吸附波研究

Ｒｈ（Ⅲ）在０．１ｍｏｌ／Ｌ ＨＡｃ－０．１ｍｏｌ／Ｌ ＮａＡｃ，１。６０×１０＾－５ｍｏｌ／Ｌ５－Ｂｒ－ＰＡＤＡＰ和０．００２５％ＯＰ溶液（ＰＨ≈４．７）中，良好的极谱波，峰电位Ｅｐ＝－０．６４Ｖ（ｖｓ．ＳＣＥ）．Ｒｈ（Ⅲ）浓度在３．９０×１０＾－９～６．８０×１０＾－７ｍｏｌ／Ｌ（即０．４０～７０ｐｐｂ）与峰电流成线性关系；检出下限为１．９×１０＾－９ｍｏｌ／Ｌ。作直线法测定配合比为：Ｒｈ（Ⅲ     

吸附还原计时电位溶出法测定钯

用悬汞电极在ＨＡｃ－ＮａＡｃ介质中（ｐＨ４．２），用还原计时电位溶出分析法研究了Ｐｄ（Ⅱ）－１－（２－吡啶偶氮）－２－萘酚（ＰＡＮ）络合物。其适宜条件为：ＮａＣｌ０．１６ｍｏｌ／Ｌ，ＰＡＮ６．０×１０＾－６ｍｏｌ／Ｌ，乙醇１０％（Ｖ／Ｖ），电解电位０．００Ｖ（ｖｓ．ＳＣＥ）。线性范围为２．４×１０＾－１１￣９．４×１０＾－８ｍｏｌ／Ｌ，络合物组成为Ｐｄ（Ⅱ）：ＰＡＮ＝１：１。试验了２０多种金属离子     

电渣重熔用CaF2＋Al2O3和CaF2＋Al2O3＋CaO系熔渣传氧的研究

利用ＺｒＯ２固体电解质氧浓差电池测定了电渣重溶用ＣａＦ２＋Ａｌ２Ｏ３和ＣａＦ２＋Ａｌ２Ｏ３＋ＣａＯ系熔渣的氧渗透率，考察了熔渣成分及温度对熔渣传氧性能的影响。在１６７３－１８７３Ｋ和０．１ＭＰａ的氧气氛下，测得这两个渣系熔渣的氧渗透率分别为１×１０＾－２０－６×１０＾－１９和１×１０＾－２１－５×１０＾－１８ｍｏｌＯ２．ｃｍ＾－１．ｓ＾－１；随ＭｎＯ２，Ｆｅ２Ｏ３，Ｃｒ２Ｏ３，ＴｉＯ２，ＣａＦ２含     

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。     

MoO3—MoO2—H2O—H2系平衡及400—700℃Mo—O系相图

使用自行设计的受控气氛热重装置研究了ＭｏＯ３－ＭｏＯ２－Ｈ２Ｏ－Ｈ２系平衡，在ＰＨ２Ｏ／ＰＨ２从０．４１２至０．６０９，温度从４００至５３４℃范围内直接测定了反应：ＭｏＯ３＋Ｈ２＝ＭｏＯ２＋Ｈ２Ｏ（ｇ）的平衡常数与温度间的关系为１ｇＫｐ＝０．７０２－７３９．８／Ｔ。获得２９８．１５Ｋ下ＭｏＯ３标准生成焓及绝对熵分别为：－８４５．７５ｋＪ·ｍｏｌｅ＾－１及７８．１６Ｊ·Ｋ＾－１·ｍｏｌｅ＾－１．实验     

阻抑动力学法测定铈的新指示反应研究：Ce（Ⅲ）—H2O2—水杨？…

在碱性介质中,铈能显著地阻抑Ｈ２Ｏ２氧化水杨基荧光酮褪色的指示反应,研究表明该动力学反应对铈为一级,测得反应的表观活化能力为２８．７５ｋＪ／ｍｏｌ。据此建立了测定痕量的动力学分析法,测定条件为ＳＡＦ：４．０×１０＾－５ｍｏｌ／ｌ,Ｈ２Ｏ２;０．０１０％,ＮａＯＨ：２．０×１０＾－２ｍｏｌ／ｌ,５０℃,线性范围０．０４μｇ／ｍｌ－０．４４μｇ／ｍｌ,方法检测限为０．０２μｇ／ｍｌ。     

Au—（Ⅲ）—5—Br—PADAP配合物吸附波的研究

在ｐＨ４．３０的ＨＡｃ－ＮａＡｃ缓冲液中，Ａｕ（Ⅲ）与５－Ｂｒ－ＰＡＤＡＰ经沸水浴加热形成１：１紫色配合物，在示波极谱仪上－０．６０Ⅴ（ｖｓ．ＳＣＥ）产生一灵敏的配合物吸附波。线性范围５．０×１０＾－８～２．００×１０＾－６ｍｏｌ／Ｌ，检出限２．０×１０＾－８ｍｏｌ／Ｌ。研究３０多种离子的干扰及分离条件。用聚氨酯泡沫塑料分离金用于矿样中金的测定，结果良好。     

阻抑动力学法测定铈的新指示反应研究——Ce(Ⅲ)-H_2O_2-水扬基荧光酮体系

在碱性介质中,铈（Ⅲ）能显著地阻抑Ｈ２Ｏ２氧化水扬基荧光酮（ＳＡＦ）褪色的指示反应,研究表明该动力学反应对铈（Ⅲ）为一级,测得反应的表观活化能为２８．７５ｋＪ／ｍｏｌ。据此建立了测定痕量铈的动力学分析法,测定条件为ＳＡＦ：４．０×１０－５ｍｏｌ／ｌ,Ｈ２Ｏ２：０．０１０％,ＮａＯＨ：２．０×１０－２ｍｏｌ／ｌ,５０℃。线性测定范围０．０４μｇ／ｍｌ～０．４４μｇ／ｍｌ,方法检测限为０．０２μｇ／ｍｌ（Ｃｅ）。当溶液中的铈含量为０．１６μｇ／ｍｌ时,３～８倍量的轻稀土,５～１１倍量的重稀土和同倍量的铀和钍等不干扰测定。测定了按不同稀土矿的稀土元素配分合成的样品中的铈含量,结果满意。     

吐温80—H2O2化学发光新体系测定痕量lr（lV）

建立了吐温８０－Ｈ２Ｏ２体系测定痕量铱的新的化学发光分析法，方法的检测限为３．０×１０＾－９ｇ／ｍｌ，线性范围为１．０×１０＾－８～１．０×１０＾－５ｇ／ｍｌ，测定１００ｐｐｂ铱溶液的相对标准偏差为６．５％。     

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).     

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.     

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.     

Growth Kinetics of Single Inclusion Particle in Molten Melts

On the basis of the single-particle framework, a new theory on inclusion growth in metallurgical melts is developed to study the kinetics of inclusion growth on account of reaction and collision. The studies show that the early growth of inclusion depends on reaction growth and Brawnian motion collision, and where the former is decisive, the late growth depends on turbulence collision and Stokes＇ collision, and where the former is dominant; collision growth is very quick during the smelting process, lessened in the refining process, but nearly negligible in the continuous casting process.