基于PLC层绕机张力与排丝系统的设计与分析

排丝系统是焊丝生产的关键系统之一，其控制的好坏直接影响到焊丝的质量。目前的排丝机多采用零角度排丝，可靠性低。现从方便性及实用性的角度出发设计一套自动排丝系统，整个系统以西门子系列S7-200可编程序控制器作为控制核心。设计了硬件控制系统，并搭建整个系统的仿真模型。仿真结果表明：设计的自动排丝系统能实现高精度自动排丝。     

锂离子铝壳电池模组焊丝末端智能监测系统研究

针对锂离子铝壳电池模组在冷金属过渡焊接过程中因焊丝卡丝、断丝现象造成的模组漏焊、报废问题,设计一种焊丝末端自动监测、智能控制系统。通过在焊机送丝柜加装焊丝监测传感器,实时监测并上传焊丝状态,控制系统针对监测的焊丝状态控制焊接系统执行模组焊接工作,实现模组在焊接过程中焊丝状态的自动监测、焊接状态的智能控制,保证模组生产稳定可靠,提高模组焊接的一次合格率。采用该焊丝状态自动监测、智能控制方案,能够有效降低锂离子电池模组在生产过程中因焊丝卡丝、断丝造成的模组焊接质量问题,提升模组焊接质量,降低设备平均故障间隔时间(MTBF),提升设备综合效率(OEE),具有较强的经济实用意义。     

激光焊自动送丝系统

针对拼接板材间隙较大,焊接过程容易出现漏焊的情况,设计了自动送丝系统。送丝系统主要由驱动机构、送丝轮和矫直机构组成,其中焊丝矫直机构,使焊丝在进入送丝软管前不发生弯曲。通过理论计算及实际测试,该激光送丝焊接系统所允许的间隙量为0.3 mm,保证焊接过程的稳定性及焊缝的一致性。     

基于PLC的镍板对接等离子弧焊过程控制

为了实现等离子弧焊过程自动化控制，文中根据等离子焊接工艺对控制系统的要求，设计了以欧姆龙CP1H型PLC为控制运算核心结合触摸屏人机界面技术的控制系统。分析了等离子弧焊过程的特点，以及控制核心PLC在焊接过程的控制对象及控制时序。系统选用两台独立的焊接电源作为维弧和主弧电源，增强了系统的稳定性和抗干扰能力，选用RS-485进行PLC与触摸屏的数据传输，对相应焊接参数进行集中化控制调节。选用Easy Builder 8000设计软件构建了触摸屏人机操作界面，系统的介绍了整个系统的组成及相互关系。最后采用不填丝熔焊和ERNi-1焊丝作为填充材料两种焊接工艺，对6 mm厚度的N6镍板进行对接工艺试焊，焊缝成形良好，系统运行安全可靠，并具有较高的可维护性，实现了等离子弧焊过程的自动控制。     

数字化推拉送丝CO_2焊接系统

采用以DSP(数字信号处理器)和CPLD(复杂可编程逻辑器件)为控制核心的数字化电源平台,结合转动惯量小、响应速度快、送丝稳定的交流伺服电机推拉送丝部分,研制了数字化推拉送丝CO2焊接系统.以缓冲器为桥梁,设计了将交流伺服推拉丝与带编码器速度反馈的等速送丝融为一体的双电机推拉送丝系统.根据推拉送丝CO2焊接过程的特点,设计了焊丝的运动曲线,并提出了与焊丝运动相对应的电流、电压波形控制方案.通过软件编程的方式实现了推拉送丝CO2焊接工艺.整个熔滴过程均匀一致,焊接飞溅小,焊接热输入量小.     

其它焊接方法

自动焊过程中，焊丝送丝性能是影响焊接接头质量的关键因素，以与焊丝送丝性能密切相关的焊丝表面状态为研究对象，以焊丝表面平坦面所占比例LD／LT及平坦面宽度偏离率KY描述焊丝表面状态，结合送丝性能与表面状态的关系，提出评价焊丝送丝性能的判据：     

其它焊接方法

自动焊过程中，焊丝送丝性能是影响焊接接头质量的关键因素，以与焊丝送丝性能密切相关的焊丝表面状态为研究对象，以焊丝表面平坦面所占比例LD／LT及平坦面宽度偏离率KY描述焊丝表面状态，结合送丝性能与表面状态的关系，提出评价焊丝送丝性能的判据：     

药芯焊丝自动配粉控制系统的设计

主要介绍了应用于药芯焊丝自动配粉生产线的配粉控制系统的硬件组成、控制原理、程序设计，该系统实现了满足药芯焊丝生产要求的高精度快速自动化粉料配制。     

焊丝校直器在自动焊送丝系统中的应用

自动焊的送丝过程极其复杂,在自动焊的工业化应用中,由于送丝导致的问题如设备停机、焊接缺陷等十分常见。本文研究了焊丝校直器在自动焊送丝系统中的作用,并分别通过检测送丝过程、焊接过程及最终的产品焊接质量,证明了安装焊丝校直器有助于稳定自动焊送丝过程,并通过实际运用解决了困扰自动焊多年的送丝问题,产生了巨大的经济效益,同时为今后自动焊设备送丝系统的研发指明了方向。     

数字化交流伺服CO2焊推拉送丝系统

以运动控制卡对转动惯量小、响应速度快的交流伺服电机控制为核心,采用缓冲器为桥梁,研制了等速送丝和推拉送丝相结合的CO2推拉送丝系统.设计了基于编码器速度负反馈的PWM送丝调速电路,可以有效补偿负载变化和电网电压波动造成的转速变化,控制精度高、送丝稳定.以交流伺服电机为基础,设计了推拉送丝机构,实现了焊丝的送进-回抽.根据推拉送丝CO2焊接的特点,设计了焊丝的运动曲线,通过对运动控制卡的编程实现了焊丝的实时送进-回抽控制.该系统抗干扰能力强、工作稳定,最高推拉送丝频率可达90 Hz.     

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.     

新型的治疗阿尔茨海默氏症药物(1-二甲基磷酰基-2,2,2-三氯)-乙基-1-醇烟酸醋对体外神经细胞的作用

目的: 观察本实验室合成的一种治疗阿尔茨海默氏症(AD)的药物(1-二甲基磷酰基-2, 2, 2 -三氯)-乙基^-1-醇烟酸醋(NMF),对体外培养的皮层神经细胞活性的影响以及对海人藻酸(KA)所致的神经损伤的保护作用。方法: 采用体外培养皮层神经元的方法,解剖分离 15 d胚胎小鼠皮层神经细胞, 接种于 96孔板,48 h 后加药并培养 72 h,以 MIT 法 观察 NMF 对小鼠皮层神经细胞活性的影响;同时将接种于 24 孔板的细胞预先给予 NMF,d 3 时加或不加KA处理后,以台盼蓝染色鉴别并计数死、活细胞,可得出细胞的存活率。结果: NMF 明显促进胎鼠皮层神经元活性,其中 NMF1、0. 1、10nmol·L^-1促进神经元活性增殖率分别高达 34.7%、37.4%、36. 7%, NMF 明显促进正常胎鼠皮层神经元存活卒,与对照组比较,10nmol·L^-1 NMF 对皮层神经元的存活率分别提高 39.3%、73.5%。 NMF能显著 对抗 KA 所致的神经元损伤,与 KA 损伤组相比, NMF0.1、10、10nmol·L^-1对损伤皮层神经元的保护率分别为 77.30%、80.10%、84.15%。结论: NMF 明 显促进胎鼠皮层神经元的洁性、提高正常皮层神经元,的存活卒,并能有效地保护KA所致的神经元损伤,提示 NMF 是一种很有潜力的治疗 AD 的药物。     

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.     

Three-Dimensional Growth of Coherent Ferrite in Austenite: A Molecular Dynamics Study

Coherent second phase often exhibits anisotropic morphology with specifi c orientations with respect to both the second and the matrix phases. As a key feature of microstructure, the morphology of the coherent particles is essential for understanding the second-phase strengthening eff ect in various industrial alloys. This letter reports anisotropic growth of coherent ferrite from austenite matrix in pure iron based on molecular dynamics simulation. We found that the ferrite grain tends to grow into an elongated plate-like shape, independent of its initial confi guration. The fi nal shape of the ferrite is closely related to the misfi t between the two phases, with the longest direction and the broad facet of the plate being, respectively, consistent with the best matching direction and the best matching plane calculated via the Burgers vector content(BVC) method. The strain energy calculation in the framework of Eshelby's inclusion theory verifi es that the simulated orientation of the coherent ferrite is energetically favorable. It is anticipated that the BVC method will be applicable in analysis of anisotropic growth and morphology of coherent second phase in other phase transformation systems.     

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).     

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.