基于OpenGL的数控车削加工仿真系统的研究

以Visual C＋4-6．0为开发工具，利用OpenGL技术开发了在Windows系统下运行的数控车削三维仿真加工系统。系统完成了主要功能模块，包括程序编辑与处理模块、仿真显示模块、主界面模块等的设计，经实例验证达到了预期的设计要求。     

基于STEP-NC的数控铣削仿真系统的研究

STEP-NC是STEP向数控领域的扩展.STEP-NC使CNC与其它CAX系统之间实现了信息的双向流通,丰富了数控程序的信息含量,提高了CNC的智能化水平.文章利用Visual C 编程语言及OpenGL图形库实现了一个基于STEP-NC的数控铣削仿真系统,构建了基于STEP-NC的软件,规划了其体系结构,论述了STEP-NC类库的设计过程.随后,给出了系统各功能模块的实施细节,分析了各模块实现的关键技术,着重介绍了系统各功能模块的设计与实现,并给出了程序算法及相关流程图.验证了STEP-NC数据模型的可行性.     

虚拟数控铣削过程的实时建模

以三角片离散法为基础实现数控铣削过程的实时建模;提出了局部搜索算法,用其搜索发生切削关系的点阵并修改其高度值;同时优化了重绘三角片过程中三角片法矢的计算;最后运用显示列表刷新方法来加快重新绘图的速度.实例表明此方法提高了数控铣削仿真的速度和显示效果.     

数控铣床的自动编程和程序分析

在CAXA-ME系统中,通过几何建模、建立刀具路径、后置处理自动生成CNC程序代码,根据具体的数控系统和机床性能参数,对程序进行分析和修改,以适应数控铣削的要求.     

基于OpenGL和Pro／E的轴向振动钻削仿真技术的研究

提出将虚拟现实技术应用于轴向振动钻削仿真系统中,该系统以VC+ +为开发平台,采用Pro/E对钻头部件进行几何建模;利用Rhino转存为3ds文件格式;利用OpenGL和VC+ +将3ds文件导入仿真环境,用重画技术和动态双缓冲技术对动态物体进行行为建模;从而模拟整个轴向振动钻削过程.     

数控铣床仿真系统

基于刀具与工件离散的方法，采用VC 语言开发了数控铣削过程的三维动态仿真系统。本仿真系统能够对数控加工程序进行编辑、检验和调试，实现了数控铣削加工过程的三维动态仿真，能够检测出加工中可能出现的干涉和碰撞。     

基于Visual C++与OpenGL的风电机组仿真系统研究

以风力发电机为研究对象,详细阐述了利用Visual C++与OpenGL实现风力发电机各部件的建模过程,利用显示列表与双缓存技术实现三维模型的动画显示,再通过网络通信实时传递仿真数据,实现风电机组模型与实际风电机组的联动,以达到系统的动态仿真.系统具有良好的实时性、交互性及动态仿真能力,为进一步研究风力发电机在线实时动态监测奠定基础.     

基于VC＋＋的弧焊机器人离线编程系统设计

针对MOTOMAN-UP系列机器人,在PC机的Windows平台上利用VC++开发了弧焊机器人离线编程系统.介绍了该系统的组成、功能及其设计方法.该系统能对任意马鞍形工件规划出焊枪的运动路径与姿态,且按比例同步显示工件;集成了机器人通信模块和运动学仿真模块,并自动导入工件,不仅能单步生成作业指令,而且可自动生成作业文件;采用OpenGL技术建立三维工件模型,实现工件的显示、旋转、缩放等功能.通过以太网,对PC机中的作业程序和机器人控制器中的作业程序进行相互传输,实现了弧焊机器人的离线编程及远程控制.     

铣削加工过程动力学建模仿真技术研究进展

从数控铣削加工过程铣削力建模仿真、颤振离线预测出发,分析了铣削力建模方法、颤振产生的机理.论述了铣削力仿真、预测控制颤振的重要性和必要性以及国内外的研究现状,并指出了该领域今后主要的研究方向.     

基于OpenGL的数控车削加工图形仿真系统研究

以数控车削加工为研究对象,开发了数控加工图形仿真系统.首先建立了适合车削加工几何特征的数据结构,利用LEX语言读取数控代码获得刀位轨迹及其与毛坯相交数据文件;然后以VC+ +6.0和OpenGL为平台,采用参数化建模方法构建加工对象的三维几何模型;最后,读取仿真数据驱动仿真过程实现.该系统实现了NC程序的快速准确验证,且避免了繁琐的布尔集合运算,使得图形生成速度与质量均得到较好的保证.     

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.     

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.     

Theoretical Analysis for the Motion and Temperature of Melt Droplets in Spray Degassing Process

The motion of melt droplets in spray degassing process was analyzed theoretically. The height of the treatment tank in spray degassing process could be determined by the results of theoretical calculation of motion of melt droplets. To know whether the melt droplets would solidify during spraying process, the balance temperature of melt droplets was also theoretically analyzed. Then proof experiments for theoretical results about temperature of melt droplets were carried. In comparison, the experimental results were nearly similar to the calculation results.     

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.