储能单面凸焊数控系统人机交互界面设计

储能单面凸焊数控系统是基于实现汽车刹车蹄片与钢网焊接而设计的控制系统,介绍了储能单面凸焊数控系统的结构,根据储能单面数控焊接控制过程设计一种基于触摸屏的人机交互界面。通过触摸屏与主控板的通讯可以方便实时监控焊接状态、手动操作控制、多组参数存储及调用及焊接过程故障检测。     

电阻焊一次成形过渡电极的设计

分析了单面多点凸焊、环凸焊在生产实际中电流分配不均的问题和解决的办法，并对过渡电极加以改进，使焊接质量达到了稳定控制。     

焊接热循环数据采集系统的设计与数据处理

介绍了电弧焊热循环过程中热影响区温度场数据采集系统的硬件设计和软件实现方法。基于VB语言设计的系统主程序能实现数据采集、存储、处理和显示热影响区在焊接热循环过程中的实时温度与时间关系曲线。并对SA335 P91钢管对接全位置固定单面焊双面成形时左右焊道交汇处闭合小孔的焊接热参数进行了实际测量。     

逆变式电阻点焊机8098单片机控制系统

介绍一种应用于逆变式电阻点焊机的８０９８微机控制系统。文中介绍了系统的硬件、软件和系统的功能。该系统通过软件编程产生两组相差１８０°的ＰＷＭ控制信号，用以控制焊接电流，同时实现了逆变点焊焊接电流递增控制。系统充分发挥了微机控制的灵活性，扩大了点焊机的应用范围。     

铝合金与钢的电阻凸塞焊

采用电阻凸塞焊新方法对A6061铝合金和Q235低碳钢进行焊接,观测了接头微观形貌并检测了接头特征区域的化学成分,对接头的力学性能进行了测试。结果表明:在电阻凸塞焊中,以钢/钢同种材料界面取代铝/钢异种材料界面实现了接头的可靠连接,避免了在焊接接头产生较多脆性的金属间化合物。与普通点焊的接头相比,电阻凸塞焊接头的力学性能有明显的提升;工艺孔直径为10.0 mm时,接头最大抗剪力达到6.28 kN,接头断裂属于塑性断裂。对于铝合金/钢异种材料的连接,电阻凸塞焊是一种有效的工艺方法。     

电阻凸焊在钢筋连接中的应用

电阻凸焊是一种操作简单、变形小、生产率高且环保的优良焊接工艺。将电阻凸焊应用于钢筋连接,既节约钢材,又能提高结构承载力。通过大量的试验与理论分析,充分探索这种成型工艺的可行性,主要对钢筋焊接过程中容易出现的问题,采取相应的控制策略,以期获得外观质量与力学性能均符合规范要求的优良焊缝接头。此研究成果对采用电阻凸焊进行各种类型钢筋的焊接具有一定的参考。     

发展CuCo2Be合金电极的必要性

电阻焊接头类型可分为搭接和对接两类。搭接焊按工艺方法又可分为点焊、缝焊和凸焊。对接焊则可分为电阻对焊和闪光对焊。各种电阻焊电极既是焊件的夹持具,也是工件焊合时传递压紧力或顶锻力的传力件,又是向焊件传输电流的导电件。点焊、缝焊、凸焊以及电阻对焊主要依     

埋弧焊工艺参数优化与模型建立

为快速、准确地获得埋弧焊工艺参数,本文利用单元正交多项式回归设计方法对中、薄板埋弧焊单面焊双面成形焊接工艺参数与板厚δ的关系进行了优化试验,并利用"SPSS"软件对试验结果进行了统计分析与检验,建立了焊接工艺参数与板厚δ的数学模型。该模型不仅可以用来确定中、薄板埋弧焊单面焊双面成形焊接工艺参数,而且对研究建立中、薄板埋弧焊计算机控制系统具有参考价值。     

真空电阻凸焊过程的有限元模拟分析

采用真空电阻凸焊进行MEMS器件的封装,可以提高成品率,降低成本.针对MEMS真空电阻凸焊过程建立热、电、结构三场耦合的有限元模型,通过分析得到凸焊筋的压溃过程、焊核的形成过程等一系列结果.结果表明,凸焊筋的压溃主要发生在通电过程的前半部分时间内,而以后的通电时间主要是凸焊筋部分金属熔化,最终形成凸焊焊核的过程.在此基础上分析凸焊筋角度对焊接质量的影响,凸焊筋角度为60°时得到的焊核较大.最后进行焊接以及焊后拉伸试验,试验结果与模拟结果一致.     

大型复杂工件焊接的自动化解决方案

通过对轿车地板通道总成焊接工艺分析,设计开发出一种新型焊接工艺流程。实现了大型复杂工件的多标准件凸焊全过程的自动化控制,加快了生产节拍,稳定了产品焊接质量,减少了操作工人数量,减轻了工人劳动强度,压缩了生产场地使用面积,从而有效地提高了劳动生产率。     

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.