Relationship between color and composition of Cu-Mn-Zn alloys

1　ＩＮＴＲＯＤＵＣＴＩＯＮＩｔｉｓｆｏｕｎｄｔｈａｔＮｉｃａｎｍｉｇｒａｔｅｆｒｏｍａｎａｌｌｏｙｉｎｔｏｔｈｅｈｕｍａｎｓｋｉｎｂｅｃａｕｓｅｏｆｉｔｓｒｅａｃｔｉｏｎｗｉｔｈｔｈｅｓｗｅａｔａｎｄｃａｎｇｉｖｅｒｉｓｅｔｏｓｅｎｓｉｔｉｚａｔｉｏｎｗｉｔｈｔｈｅｄｅｖｅｌｏｐｍｅｎｔｏｆａｌｌｅｒｇｉｅｓ[1～3] .Ｔｈｅｒｅｆｏｒｅ ,ｓｔｒｉｃｔｅｒｓｔａｎｄａｒｄｓａｎｄｒｅｇｕｌａ ｔｉｏｎｓａｒｅｍａｄｅｔｏｌｉｍｉｔｏｒｐｒｏｈｉｂｉｔｔｈｅｕｓｅｏｆｐｒｏｄｕｃｔｓｗｉｔｈｎｉｃｋｅ…     

Relationship between cooling rate and electrochemical performance of melt-spun AB_5 alloy

1　INTRODUCTIONNi/MHsecondarybatterieshaverapidlybeendevelopedandgraduallysubstitutedforNi/Cdbatter iesintherecentdecadeduetoitshighspecificenergydensityandhavingnopoisonouselementcadmium .TheactivematerialofnegativeelectrodewidelyusedinNi/MHsecondarybatteriesisAB5 typehydrogenstoragealloynowadays .However ,itisstillneededtoimprovethecomprehensive propertiesofAB5 typehydrogenstoragealloyforprolongingtheservicelifeofNi/MHbatteries .Anormalmethodtoimprovethecomprehensivepropertiesofthe…     

Relationship between tensile and primary creep properties of near γ-TiAl intermetallics

This paper presents the tensile and primary creep behaviour of fully lamellar microstructures for three near γ-TiAl compositions: binary TiAl, ternary TiAl+W and TiAl+NbMnWMoSi. Reducing the lamellar interface spacing or aging to precipitate β along interfaces increases the 760 °C tensile strength. Primary creep at stresses from 140 to 276 MPa and 760 °C is characterized in terms of the instantaneous strain occurring during creep loading and a subsequent primary transient. The presence of interface β precipitates reduces the instantaneous strain and increases the time to 0.5% creep strain. Reducing lamellar interface spacing does not influence the instantaneous strain, but decreases the strain rate during the primary transient. Correlating the creep response with deformation structures after primary creep suggests that the instantaneous strain depends on the mobility of interface dislocations and the primary transient depends on dislocation mobility in both the lamellar interfaces and γ lamellae.     

Relationship between microstructures and mechanical properties of resistance spot welded joint of spring steel

0IntroductionSpring steel(65Mn,60Si2Mn) has a high carbon e-quivalent (Ceq≈0.9) and strong hardening capacity. Inresistance spot welding process, the cooling rate of nuggetand heat-affected zone is quite rapid (about 104 -105℃/ s),and martensite which has high hardness forms atthe spot welded joint. Martensite structure, which is hardand brittle, makes mechanical properties of the resistancespot welded joint of spring steels greatly decline. There-fore, the weldability of resistance spot w…     

Relationship between solids flux and froth features in batch flotation of sulphide ore

The froth features in the batch flotation of a sulphide ore were investigated by using the digital image parameters of the froth, the small number emphasis（Nsne）, the average grey level（Dagl） and the instability number （Nins）, under different conditions of impeller speeds and aeration rates. It is found that the value of Nsne is strongly dependent on the average bubble size of the froth and Dagl on the volume fraction of solid in the froth, and the froth features during the batch flotation are influenced by impeller speed and aeration rate. A kinetic model of the concen- trate solid flux was developed which relates the flotation process to the image parameters, Nsne and Dagl of the froth and predictions are well consistent with the experimental data.     

Relationship between the types of binary alloy phase diagrams of Ⅷ and IB group elements and the Mendeleev numbers

The relationship between the types of binary alloy phase diagrams of VIII and IB group elements and the Mendeleev numbers was discussed for the first time using the VIII and IB group elements as solvent metals (A) and the other elements as solute metals (B), basesd on their alloy phase diagram types. The Mendeleev numbers of the solvent metals and the solute metals were expressed as MA and MB, respectively. A two-dimension map of MA/MB was drawn. It is indi-cated that there is an oblique line in the map, which divides the binary alloy phase diagram types of solvent metals intotwo symmetry parts, the phase diagram types of the other elements with solvent metals located at the above or down ofthe line respectively, while on the line, ΔM= 0. The phase diagrams between the solvent metals basically are simple systems, mainly belong to the types of continues solid solution and the peritectic (about 40% for each type). The solvent metals can be divided into three groups: Co, lr, Rh, Ni, Pt, and Pd as the first group; Ag, Au, and Cu as the second group;and Fe, Os, and Ru as the third group. The characteristics of the phase diagrams formed between the elements in each group were discussed. About 80% phase diagrams belong to complex systems and less than 20% belong to the simple systems. The regular variation of the chemical scale, the metallic radii of the atoms, the number of valence electrons, and the first ionization energy with the Mendeleev numbers and the crystal structure were introduced as well.     

Relationship between elongation and porosity for high porosity metal materials

１　ＩＮＴＲＯＤＵＣＴＩＯＮＨｉｇｈｐｏｒｏｓｉｔｙｍｅｔａｌｍａｔｅｒｉａｌｓａｒｅｗｉｄｅｌｙａｐｐｌｉｅｄｄａｉｌｙｆｏｒｔｈｅｉｒｓｐｅｃｉｆｉｃｃｈａｒａｃｔｅｒｉｓｔｉｃ［１～５］．Ａｓｅｎｇｉｎｅｅｒｉｎｇｍａｔｅｒｉａｌｓ，ｔｈｅｍｅｃｈａｎｉｃａｌｐｒｏｐｅｒｔｉｅｓａｒｅｂａｓｉｃｆｏｒｔｈｅｍ［１，３，５］．Ｐｏｒｏｕｓｂｏｄｉｅｓｎｅｅｄｂｅｔｅｎｓｉｏｎｅｄ，ｐｒｅｓｓｅｄ，ｂｅｎｔｏｒｓｈａｐｅｄｉｎｓｏｍｅｃａｓｅｓ，ｓｏｈｉｇｈｐｏｒｏｓｉｔｙｍｅｔａｌｍａｔ…     

Relationship between solid fraction of slurry and property of steel/mushy Al-20Sn semi-solid bonding

The slurry of Al-20Sn alloy was prepared using electromagnetic-mechanical stirring method.The bonding of steel/mushy Al-20Sn was conducted using casting rolling technique.The bonding parameters were 505℃ for preheat temperature of steel plate and 10mm/s for rolling speed.The interfacial mechanical property and structure of steel/mushy Al-20Sn bonding plate were studied.The results show that the relationship between solid fraction of Al-20Sn slurry and interfacial shear strength of bonding plate is S=52.9 0.998ψs-0.0144ψs^2(where S is interfacial shear strength,ψs is solid fraction.)The largest interfacial shear strength is 70.2MPa when solid fraction is 34.6%.The interface of bonding plate is made up of Fe-Al compound and Fe-Al solid solution alternatively.     

Relationship between heat treatment and corrosion behaviour of Mg-3.0%Nd-0.4%Zr magnesium alloy

The corrosion behaviour of Mg-3.0Nd-0.4Zr （NK30） magnesium alloy was investigated in as-cast （F）, solution treated （T4） and peak-aged （T6） conditions in 5% NaCI solution by immersion tests and electrochemical measurements. The results of immersion test show that NK30 alloy exhibits better corrosion resistance in F condition than it does in the other two conditions due to the more compact corrosion film formed on alloy in F condition. The potentiodynamic polarization curves show that the overpotential of cathodic hydrogen evolution reaction on NK30-F is much higher than that on NK30-T4 and NK30-T6. The corrosion potentials of NK30 increase in the following order： F〈T4〈T6. The results of electrochemical impedance spectroscopy （EIS） also confirm that the corrosion film of NK30-F plays a more protective role than that of NK30-T4 and NK30-T6.     

Effects of Oxygen Increasing/Decreasing Processes on Surface Characteristics of Superalloy Powders and Properties of Their Bulk Alloy Counterparts: Powders Storage and DegassingEI北大核心CSCD

采用场发射扫描电镜(FESEM)、X射线光电子谱(XPS)、高角环形暗场扫描透射电镜(HAADF-STEM)以及程序升温脱附与质谱联用(TPD-MS)等表征手段研究了不同窄粒度范围镍基高温合金粉末的原始表面状态以及存储和脱气等增/降氧过程对合金组织和性能的影响。结果表明：不同粒度原始态粉末的表面组成均为Ni O/Ni(OH)₂、TiO₂、CoO和Cr₂O₃,0～15μm粒径粉末(细粉)和150～180μm粒径粉末(粗粉)平均氧化膜厚度分别为3.32和10.90 nm。细粉和粗粉在空气环境中存储后氧含量逐渐增大,在3～10 d达到稳定值,分别约为250×10^-6和40×10^-6。存储后0～53μm粉末制备的块体合金氧含量升高,室温、650℃和750℃拉伸强度变化不大,但塑性下降,合金在650℃、890 MPa和750℃、530 MPa的持久性能均下降。0～15μm细粉加热过程中(室温～1000℃)会发生气体脱附,存在明显脱附峰的气体包括CO₂     

硅溶胶型壳中原材料分布及其规律研究

测定了硅溶胶型壳原材料分布及其成本分布规律,探讨了该规律与铸件的关系,这对精密铸造生产管理的材料消耗控制和成本分析有指导意义。     

我国大学本科教学管理制度的三个缺陷及改革

通过15所大学师生和管理人员的访谈和问卷调查，结合对相关教学管理制度文本的分析，提出了我国大学本科教学管理制度现存的三个主要弊端：以控制为中心，教学选择性和自主性不足；以管理者为中心，制度的平等性和服务性不足；以校部为中心，院系教学管理活力不足。作者认为，适应市场体制和新的大学教学管理的要求，大学要确立以师生为本、以服务为本、以院系为本的新理念，降低教学管理重心，放松教学管理规制，强化教学支持服务。     

详解摆线轮磨削软件与数控系统的关联

对于具有复杂曲面轮廓的RV减速器摆线轮的制造,通过辅助制造软件对齿廓进行设计和修形并根据最终齿廓曲线自动生成G代码数控程序通过数控系统直接读取加工,可以减轻工人的编程工作量,提高生产效率。     

论教育关系的调整机制

作为一种特殊的社会关系，教育关系是教育关系主体围绕教育目的之实现而形成的各种关系。从教育发生学的角度看，教育关系源于人类的血缘关系，是从人类父母与子女血缘关系中分化出来的一种社会关系。教育关系经历三个发展阶段：教育关系的道德化、教育关系的等级化与教育关系的法律化。对教育关系进行调整的规则有两种形式：一为不成文的规则，即潜规则；一为成文规则，即显规则。从不成文的规则演化为成熟的法律体系，经历了一个漫长的历史过程。     

能量调节技术在车载液压系统的应用

为解决车载液压行车发电瞬态指标控制问题,设计基于能量调节的泵阀并联液压马达调速系统.研究能量调节技术在车载液压发电系统中的应用,对液压系统主要元件进行选型.参考标准GB/T 2820.5—2009,进行液压发电试验,并对比采用能量调节技术前后得到的试验数据.结果表明:应用能量调节技术的车载液压发电装置,其主要交流发电技...     

阀泵并联变模式调速实验系统设计

为了实现大功率液压马达调试系统低速平稳快速启停,同时较好地解决液压马达调速系统效率高和响应快的矛盾,设计一种阀泵并联变模式液压马达调速系统,并利用LabVIEW软件完成了系统实验台的监控和数据采集。结果表明:该液压马达调速系统具有较好的低速稳定性,对负载扰动有较强的鲁棒性,调速效果比较理想。     

二次调节静液驱动技术在车辆中的应用

本文介绍了一种新型静液驱动车辆的基本原理及工作特点。详细地分析了在采用了二次凋节静液驱动技术后，车辆的经济性有所提高。     

泵阀联合调速在电动叉车中的应用

为解决电动叉车液压系统在启动和位置调整时响应速度慢等问题,提出了一种采用泵阀联合调速的解决方案。针对电动叉车工作特点,提出了泵阀联合调速的控制方式,在泵控环节,通过引入模糊控制作为算子函数,实时整定PID参数,从而提高电机在不同工况下的自适应能力;在阀控环节,采用PID控制确保输出流量的稳定性。采用Simulink和AMESim进行仿真,结果表明:采用模糊控制的矢量调速对于不同工况的适应能力有很大提高,而采用阀控则可有效提高系统响应速度。两者结合的泵阀联合调速,不仅克服了单纯变频调速响应滞后的缺点,同时对于复杂工况有很好的适应能力。     

电液位置系统的非线性校正与描述函数法分析

采用描述函数法，利用线性系统的理论和方法对电液系统进行频域分析，并且引入逻辑切换的非线性特性使其动态性能显著提高，和其它现代控制的状态反馈法相比，该方法具有简单、可行性高的优点。     

Au-Ni合金中组元的平均原子体积和偏摩尔体积的关系

在系统合金科学框架中建立有关无序合金的平均摩尔性质（体积和势能）的函数。通过对这些函数进行推导,可以得到平均摩尔体积函数、偏摩尔体积函数及派生出与成分相关的函数。在组元的偏摩尔性质和平均摩尔性质之间的普适方程、差分方程、在偏摩尔性质和平均摩尔性质之间不同参数的约束方程和普适的Gibbs-Duhem公式。可以证明从合金平均摩尔性质的不同函数计算的偏摩尔性质是相等的,但总体来说偏摩尔性质不等于给定组元的平均摩尔性质,即偏摩尔性质不能代表相应组元的摩尔性质。通过计算Au-Ni系中组元的偏摩尔体积和平均原子体积以及合金的平均原子体积,证明所建立的公式和函数的正确性。