基于以太网的异构数控机床集成实现

实现DNC系统的核心问题是解决数控机床与计算机之间的信息交换和互联.文章介绍了一种基于以太网的DNC通信技术.实现了将中央计算机的加工信息传递给机床;然后由计算机在线监视并处理机床反馈的实时信息;并且通过中央计算机协调数控机床进行协同加工.     

基于以太网的计算机与数控系统通信技术

利用一般数控机床的RS-232C串行接口研究了串行通信系统,构建了DNC网络拓扑结构,分析了基于工业以太网的DNC的通信技术,指出了该DNC通信平台的功能和特点,基于工业以太网的DNC系统性能可靠,具有广阔的应用前景.     

数控机床数据采集嵌入式适配器设计与开发

传统数控机床数据采集系统采用有线进行数据传输且采集的数据类型少,通信的移动性和数据采集的适应性不足,因此选择无线通信作为嵌入式适配器与上位机的通信方式,设计与开发嵌入式适配器实现数控机床联网与数据采集.依据通信和数据采集方面的需求,设计嵌入式适配器硬件系统,选择与定制嵌入式适配器操作系统,开发嵌入式适配器数据采集与处理软件.结果表明,嵌入式适配器实现了与上位机的无线通信,实现了数控机床数据采集与异构数据处理,提高了系统灵活性.     

一种基于Web的DNC数控机床信息采集系统

为了适应网络化制造模式下对DNC系统的功能要求,提出一种基于以太网的面向串行通信机床的DNC系统(PowerDNC).系统以ZWORLD公司生产的BL2010单板机为DNC系统控制器,从信息采集的角度,阐述了系统的物理、逻辑和程序结构,介绍了机床信息采集系统的功能模型.实验证明,系统能够实现对数控机床信息的有效管理,对提高数控设备利用率、促进产品的敏捷制造具有重要意义.     

DNC系统在车间数字化改造中的应用研究

分布式数字控制技术(DNC)不仅是一种控制和获取车间底层设备(如数控机床)信息的关键技术,也是实现数字化车间底层数字化设备与上层管理软件之间信息交互的桥梁。分析企业实现数字化车间需要DNC系统的必要性,介绍DNC系统的原理与方法;以某企业数字化车间改造中DNC系统的应用为例给出了DNC的实施方法和关键技术。实施结果表明:DNC不仅可以充分发挥数控设备的效率,而且提高了数控机床的管理水平。     

基于传感网络的数控机床故障监控系统的设计

设计一种新型的数控机床故障监控系统,通过在数控机床上安装不同类型的传感器,对易产生故障的部位进行多参数综合监控。数据采集模块负责对各种动态参数进行实时采集,并通过无线网络方式将数据传输至上位机。上位机中安装有相应的故障监控软件,将通过软件界面显示故障信息并报警。实验结果表明:基于传感网络的数控机床故障监控系统可降低机床停机率,提高机床利用率并早期预防某些隐性故障。     

基于Extreme DNC的数控中心改造方案

分析数控机床多机联网和远程通信的必要性;详细介绍基于Extreme DNC的数控中心改造方案,主要硬件模块功能、数控系统通信参数设置;该方案已在实际应用中验证通过,效果良好,具有推广应用价值。     

PC与SIEMENS数控系统通信技术

目前计算机与数控机床的实时通信主要有两种方案。一种是计算机与数控机床间的一对一通信;另一种是计算机与数控机床间一对多的通信,即网络DNC。本文主要介绍计算机与数控机床间的一对一通信技术。     

基于PC机的DNC传输软件的开发

为了解决机床数控系统对大容量数控程序的处理,开发了基于PC机的DNC传输软件.该软件采用MSComm控件和流量控制技术,结合丰富的通信参数选项,实现了数控机床的DNC工作方式,经测试其在FANUC数控系统上或通信协议相同的其它厂商的数控系统上均能正常运行,这大大提高了该软件的通用性.     

日本“日立精机”《102》系统介绍

日本“日立精机”“102-系统”是利用现有的数控机床和通用机床组成的DNC生产线;文章分别对系统的一般说明、特点、工作情况、输送流程图、成组加工系统是DNC生产线的前题等等进行了简要说明。图3幅。馆藏号:     

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。