基于PC的全软件数控系统结构设计

数控系统是一种典型的多任务实时控制系统,全软件数控系统是实现开放式数控系统的有效途径。提出采用基于PC的全软件数控系统,并对数控系统的整体结构进行了设计;提出利用Windows操作系统的分层结构,实现数控系统的强实时控制功能及非实时控制功能,解决了Windows操作系统在数控系统实时控制方面的应用,为Windows操作系统下实现开放式数控系统的软件结构模型提出了有效途径。实验证明,该方法行之有效。     

基于Windows NT的开发式数控系统多任务实时控制

本文讨论如何在流行操作系统平台、用软件实现数控系统功能，建立全软件开放式数控系统。分析了现有操作系统在实时控制领域的应用，给出了在Windows NT 实时扩展下的数控系统的结构，测试分析了系统的中断响应速度。     

基于几种不同操作系统平台的数控系统软件开发的比较研究

分析了开放式数控系统软件的特点,论述了基于DOS、Windows、RTLinux三种不同操作系统平台开发数控系统软件的方案,以及在不同系统操作系统平台上解决实时性、多任务控制问题的方法.最后提出了基于RTLinux平台开发的开放式数控系统软件的基本框架.     

基于Windows的全软件数控系统实现方法研究

以基于Windows操作系统的全软件数控系统为例,论述全软件数控系统实时控制及非实时控制两部分内容的具体安排方式及数据通信方法,并给出全软件数控系统定时时钟的测定及中断级别的提升方法,以满足数控进给加工中的加减速控制及插补运算等对实时性的要求。试验结果表明:采用这种方法实现全软件数控,可使控制系统的进给速度得到显著提高。     

基于嵌入式实时操作系统的开放式数控系统的研究

阐述了开放式数控系统的特点和要求,在比较通用操作系统和实时操作系统后,提出了基于Windows CE．NET平台开放式数控的构想,并初步介绍了在此平台上全软件数控系统的结构。     

开放式软数控系统的关键技术研究及实现

首先概述了开放式数控系统的发展现状与特点。然后对具有代表性的操作系统(包括专有实时操作系统、Linux、Windows及基于Windows的实时扩展操作系统)的实时性与开放性进行了研究与比较，并分析了SERCOS总线的性能与发展过程，指出基于Windows的实时扩展操作系统和SERCOS标准的实施是实现开放式软数控系统的两个重要技术基础。最后给出了一个基于Windows实时扩展和SERCOS总线技术的开放式软数控系统设计实例。     

基于Windows 2000下开放式数控系统软件的开发

基于PC机和Windows操作系统的开放式数控系统是数控技术的大势所趋.文章首先介绍了数控机床的发展历程,并分析传统数控系统不足和基于PC的开放式数控技术的优点的基础上,论述了基于Windows2000操作系统下,开放式数控系统软件的研究和开发过程.重点阐述了在Microsoft Visual C 下系统人机交互界面的设计、工控PC机控制运动控制卡的接口软件模块、PC机与主轴控制变频器的RS485串行口通讯软件模块的的编写,同时给出了主要程序代码.该数控系统现在已经在调试之中,并且达到了预期的加工精度和效果.     

基于PC+I/O软件化开放式数控系统框架研究

分析PC数控系统各种体系结构的优缺点,介绍PC+I/O软件化结构的设计思想以及存在的优势,研究若干关键技术的解决方案,如Windows操作系统的实时化、底层通信和实时控制等,提出基于PC+I/O软件化结构数控系统的软硬件平台设计框架.     

基于FMS开放式数控系统的研究及在线监控

柔性制造系统具有控制方式灵活,控制简单,实时性强及成本低等优点,而基于柔性制造系统的开放式数控系统可以解决传统数控系统和用于工业加工的数控应用软件所不能解决的问题。文章研究了NC嵌入PC结构的数控系统,搭建一种基于Windows操作系统"工控机+运动控制卡"的开放式数控系统硬件平台,研究了开放式数控系统的多任务划分与并行处理机制;通过组态软件WinCC设计了FMS(Flexible Manufacturing System)监控界面,并采用工业以太网、OPC技术实现FMS主控计算机与工控机的通讯。     

数控代码的编译方法研究

开放式数控系统是数控系统发展的主流方向,基于PC的全软件数控系统是实现开放式数控系统的最有效途径。全软件数控系统中,采用何种数控代码编译方法将会影响到数控加工控制过程的加工速度和加工精度。对传统数控代码的编译过程进行了细致的研究,提出了一种新的更适合于全软件数控加工的数控代码编译方法。     

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.     

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.