基于UG NX的四轴加工中心后置处理

对NX 8．0的后处理构造器进行深入研究,结合所使用的四轴立式加工中心及FANUC数控系统,开发出了适用于该加工中心及其数控系统的专用后置处理程序。通过产品加工实例,验证了该专用后置处理程序的正确性和实用性。     

基于UG/NX8.0的5轴加工中心后置处理的研究

5轴数控机床加工由于工艺方法复杂、运动部件多以及涉及多坐标轴等原因,对于目前的后置处理软件及技术提出了更高的要求。通过摸索UG/NX8.0软件后置处理功能,利用UG/Post Build功能,针对配置Heidenhain数控系统的5轴加工中心编制后置处理程序,使得开发的专用后置处理程序所生成的程序代码能够直接应用于Heidenhain数控系统的5轴加工中心。     

数控机床自动编程中后置处理程序的设计

针对MasterCAM自动编程软件中无华中I型数控系统后置处理程序的局限性，在分析MasterCAM通用后置处理程序的基础上，设计出华中I型数控系统专用的后置处理程序，并成功应用于数控机床的加工生产。     

MasterCAM后置处理程序在PMAC系统中的应用

结合PMAC多功能运动控制卡组建的三轴雕刻机床数控系统的编程特点,开发了针对此机床专用的后置处理程序,使MasterCAM生成的程序能够直接应用于此数控系统。实际应用表明,该专用后置处理程序提高了编程效率,完全满足实际使用的需求。     

数控机床自动编程中后置处理程序的设计

针对MasterCAM自动编程软件中无华中Ⅰ型数控系统后置处理程序的局限性,在分析MasterCAM通用后置处理程序的基础上.设计出华中Ⅰ型数控系统专用的后置处理程序,并成功应用于数控机床的加工生产.     

基于CimatronE的四轴后置处理软件开发

基于CimatronE平台,用VB6.0语言编写了XH715D铣削加工中心的专用后处理软件。首先,针对CimatronE刀位文件的特点,提出了该软件的后处理方式以及软件运行的原则,其次,对Cimatron E/CAM模块生成的CL文件格式、HNC-22M数控系统的规则以及XH715D铣削加工中心坐标转换数学模型进行了深入的分析,推导出该类机床后置处理转角计算公式和坐标转换计算公式。在此基础上用VB6.0语言编写了专用后处理软件的算法代码,对多个复杂曲面零件的加工刀轨文件进行后置处理,输出的数控加工程序在XH715D铣削加工中心上加工,验证了该后置处理程序的正确性。     

反镗孔加工固定循环的自动编程方法

在分析加工中心反镗孔加工动作循环及MasterCAM9.0的通用后置处理程序的基础上,提出了一种通过修改、定制MasterCAM9.0的后处理文件,开发反镗孔加工循环专用后置处理程序的方法和详细步骤。通过在加工中心上反镗一个箱体上的不规则台阶孔的加工实例表明了该方法的正确性。     

基于UG四轴后置处理软件开发

基于UG平台,用VB6.0语言编写了XH715D铣削加工中心的专用后处理软件.论文针对UG刀位文件的特点,提出了该软件的后处理方式以及软件运行的原则,并对该软件的总体构成作了阐明;对UG/CAM模块生成的CLSF文件格式、华中世纪星数控系统的规则以及XH715D铣削加工中心坐标转换数学模型进行了深入的分析与研究,推导出该类机床后置处理转角计算公式和坐标转换计算公式.在此基础上用VB6.0语言编写了专用后处理软件,对多个复杂曲面零件的加工刀轨文件进行后置处理,输出的数控加工程序在XH715D铣削加工中心上加工,验证了该后置处理程序的正确性.     

MasterCAM V8.0后置处理程序的优化设计

介绍了MasterCAM V8.0后置处理程序，针对FANUC O-M数控系统，对后置处理程序进行修改，使得修改后的后置处理程序更符合各数控系统要求。     

MasterCAM后置处理程序在SIEMENS系统中的应用

在研究MasterCAM后置处理程序格式的基础上,开发出适合SIEMENS数控系统的专用后置处理程序,解决了由MasterCAM生成的数控程序不能直接用于SIEMENS数控铣床系统加工的问题.     

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.