胶胆阀的改进

在铸工车间煤粉粘上沸腾压送系统中,胶胆阀是常用部件。与手动闸阀和电动闸阀相比,它具有体积小、结构简单、操作方便、易于实现自动控制等优点,尤其在远距离压送和多点卸料时,上述优点更为显著。但是,由于结构上的原因,这种阀在实际使用中也暴露出自身存在的缺陷。图1是一胶胆阀实例。在装配过程中,法兰突出的斜面容易将胶胆挤退,使胶胆在阀中固定不可靠。工作时,压缩空气进入阀体气腔     

生产压铸件的方法与装置:US006125911A

该装置包括一副压铸型及用于控制压铸型型腔真空的抽吸单元。抽吸单元包括真空包及压铸型。在抽气泵路中包含一个一级阀及一只与之耦合的二级阀。两只阀位置是特别设置的 ,以使二者之间形成一段调节空间。生产压铸件的过程包括抽吸型腔 ,将压铸合金射入铸型 ,取铸件 ,通过关闭两只耦合阀在抽气泵路中形成一段调节空间 ,在调节空间内测试湿度、压力和温度等参数 ,并依据测试值控制该装置。生产压铸件的方法与装置:US006125911A@戴挺     

具有反比例控制功能的新型比例压力阀的压力-流量特性试验研究

本文简要介绍一种在中高压范围内具有出口压力随磁力增大而减少的反比例功能的新型比例压力控制阀，设计了一种简单，实用，精确的流量测试方法，通过台架试验对该阀的压力－负载流量等特性进行测试，表明该阀具有较好的压力和流量特性且输出压力动态响应快。     

新型比例调速阀低温流量特性研究

介绍一种新型比例调速阀结构设计的主要特点,通过理论分析和数值计算,并应用流体仿真方法对各结构和参数进行设计和优化,研究低温环境下阀件的适应性和流量特性。通过仿真和试验验证,该新型比例调速阀在常温及低温环境中流量、压力稳定性好,且该阀具有集成化程度高、结构紧凑等特点。     

电控比例阀——可完成复杂的比例控制用的简单阀

这种电控阀是一种新型的通过电来调节流量与压力的比例阀。它的工作很象伺服机构,但大大地进行了简化:将反馈放在阀的内部。这种电控阀的一个特点是,具有伺服装置的性能,但没有伺服装置。它工作起来很象伺服装置,精确地跟踪着一个输入信号来调节输出——压力或流量。这种阀就这样工作而无需外部反馈,因此取消了伺服装置设计中的最复杂的也是最易出毛病的那部份结构。 这种新型比例流量控制阀所以能具有这种性能的一个关键,就是能实现压力补偿,即阀可以随着输入压力的变化而自动调整。伺服阀基本上是不能进行压力补偿的。它是按照遥控     

介质对金属滤毡初始气泡点压力的影响

依据国家标准,研究了介质类型和环境温度对滤毡初始气泡点压力的影响.实验结果表明,初始气泡点压力与试验选用的介质和环境温度有关,相同条件下,试验介质的密度和表面张力越大,滤毡的初始气泡点压力也就越大;环境温度越高,初始气泡点压力越低;且用95%乙醇测初始气泡点压力时所测结果受温度影响比异丙醇小.     

水压比例节流阀的滑阀静态特性仿真分析

介绍了新型水压比例节流阀的结构及特点,建立了水压比例节流阀的滑阀流量-压力方程.通过利用MATLAB/SIMULINK软件对滑阀的流量特性、压力特性和流量-压力特性仿真分析,得到了负载快进与工进时的阀芯位移范围.分析表明:在稳态情况下,负载流量与阀芯位移之间为线性关系,且负载快进时滑阀对负载流量的控制比负载工进时灵敏;当通过节流阀口的流量不变时,阀芯位移越大,滑阀的压力放大系数越小;当阀芯位移一定时,负载压降越大,通过负载的流量越小;而当负载压降一定时,阀芯位移越大,通过负载的流量越大;阀口开度越小,阀的流量-压力系数越小,阀的刚度越大,反之,阀口开度越大,阀的流量-压力系数越大,阀的刚度越小.     

可编程多功能电液组合阀的研究

介绍了可编程多功能电液组合阀的阀口独立控制原理.在不改变任何硬件的情况下,通过改变控制逻辑实现可编程多功能电液组合阀的功能,可以应用逻辑开关控制实现所有的中位机能.在进、出口节流调速时,应用组合阀可以消除或减小压力冲击,并可应用差动回路使流量再生,从而起到节能的功能.     

石墨材料在出铝真空包内衬上的应用

传统用出铝真空包内衬材料是粘土质耐火砖。在阐述其缺点之后,本文论述了选用石墨质材料代替的可行性。其材料来源广泛,易于加工,是值得电解铝厂采用的新型真空包内衬材料。     

双流法碱液加热器空泡腐蚀和防止方法

本文根据国家“八五”重点科技攻关项目－－“双流法溶出新工艺及设备研究”专题试验的初步设计提供了溶出工艺条件，通过计算分析得出碱液加热器存在空泡腐蚀，碱液加热管内壁局部碱液饱和蒸气压大于该点液体静压力，产生气泡，在碱液层流内层，速度梯度引起的压力梯度使气泡向径向移动，温度梯度使气泡沿么薇移动达到某点时，碱液饱和蒸气压接近该点液体静压力，气泡破裂或受剪切力而使气泡破裂，对加热管内壁进行强烈的冲击，并在     

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。