液压多刀车床的PLC控制系统设计

本文介绍了PLC在液压多刀车床电气控制系统的有关应用设计问题，主要内容有加工工艺要求、控制要求、PLC硬件设计和PLC软件设计等几方面内容。     

双轴镗床的PLC控制系统设计

本文介绍了ＰＬＣ在双轴镗床电气控制系统的有关应用设计问题,主要内容有加工工艺,控制要求,ＰＬＣ硬件设计和ＰＬＣ软件设计等几方面内容。     

基于Windows2000快速成型SLA控制系统的研究

首先对Windows2000的体系结构和实时性进行了分析，并指明Winodws2000是开发数控系统的理想平台，接着阐述了设备驱动程序的性能和结构，最后详细介绍了快速成型SLA控制系统的硬件结构和软件设计。     

100t高阻抗电弧炉的自动化控制系统

介绍了采用西门子公司PCS7系统为核心的高阻抗电弧炉自动化控制系统,主要包括有高阻抗电弧炉的主要设计技术参数,控制系统的硬件设计方案及组成,自动化系统的软件设计功能和主要控制对象,按照铸造生产对控制系统的要求,将整个系统划分为若干个控制子单元分别进行功能描述,详细说明了各部分的控制范围及目的,使得该套高阻抗电弧炉的控制系统能够在铸造生产的过程中全面实现工业现代化的操作、监控、信息处理和检修维护,保障了铸造生产设备的安全运行。     

用于钢轨焊接的电子束焊机控制系统的设计

通过介绍用于钢轨焊接的电子束焊机的工作原理及系统组成,对该焊机的控制原理和作用进行分析,并通过使用西门子公司的S7200系列PLC作为下位机控制核心,以工控机作为上位机核心和PMAC运动控制卡为运动控制核心的系统组成,根据该焊机的使用需求设计了PLC的控制软件及上位机软件,并对软件进行了详细说明。设备运行表明:焊机的控制系统硬件、软件设计合理,功能完善,工作可靠,满足了钢轨电子束焊接的需要。     

数字化大功率微弧氧化电源控制系统

介绍了一种数字化多自由度大功率微弧氧化电源的控制系统,该电源控制系统以TMS320F2812为控制核心,用S3C2410控制的触摸屏作为系统的人机界面.详细说明了该电源主电路结构、控制系统硬件和软件设计流程以及人机界面设计.研制出的微弧氧化电源控制系统具有恒压、恒流以及恒功率三种工作模式,每种工作模式下可以按照上位机的...     

自动化立体仓库监控系统的研究

利用PLC控制技术完成了自动化立体仓库堆垛机控制系统的硬件和软件设计,并给出了详细的I/O信号,介绍了电气控制系统中采取的安全保护措施;利用组态软件设计了自动化立体仓库的实时监控系统及信息管理系统.结果表明,所设计控制系统性能可靠,有良好的实际应用价值.     

瓦楞纸板点数分批设备控制系统设计

针对瓦楞纸板主要依靠人工分料,存在劳动强度大、生产效率低、生产成本高等问题,研制一套瓦楞纸板自动点数分批系统,根据瓦楞纸板点数分批的工艺要求设计了控制系统的硬件设备和控制方案。其中硬件部分主要有SIMATIC S7-1511-1PN可编程控制器(PLC)、分布式IO模块、脉冲输出模块、伺服驱动器和智能相机设备等。详细介绍了推板机构分批运动控制、相机设备通信控制和升降机构定位点数控制等核心技术,利用TIA Portal V14编程软件设计HMI界面,完成对系统远程控制与监测。实验结果表明:该设备可以实现瓦楞纸板自动化精准分料,具有操作简单、精度高、安全高效、节约劳动力等优点。     

某型武器装填液压系统的PLC控制研究

介绍某型武器装填液压系统的工作原理,研制以可编程控制器(PLC)为核心的控制系统,对控制系统的硬件结构、控制软件设计以及抗干扰措施等进行详细介绍.实验结果表明该PLC控制系统实现对武器装填液压系统的运动控制,达到预期控制要求.     

基于80C196KC单片机的舞蹈机器人控制系统设计

介绍了基于80C196KC单片机的舞蹈机器人控制系统的设计，详细阐述了系统的硬件实现方案和软件设计思想，该系统采用分时复用的方法，利用PWM信号对驱动电机进行控制。     

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。