数字信号处理器DSP主控GMAW焊接

阐述了焊接过程信息数字处理控制思想，实际研究了数字信号处理器9DSP）在CO2气体保护焊机中的应用，将数字信号处理器（DSP）在送丝系统的柔性化调节，引弧和收弧模式，焊接参数的一元化自调节等方面的应用作了研究和试验，通过研究和样机试验，建立了一套焊接电源的数字化，信息化，柔性化控制平台，并探讨了数字信号处理器（DSP）在CO2焊接领域中的应用优点和前景，并提出了DSP主控GMAW焊接电源全系统框图，试验证明该系统工作稳定可靠，较好地满足了工艺性能，实现了焊机控制的数字化。     

不同焊接方法对哈氏合金C-276焊缝组织和耐晶间腐蚀性能的影响

采用ASTM-G28B法进行晶间腐蚀试验,分别研究了手工GTAW和手工GMAW对哈氏合金C-276焊缝组织和耐晶间腐蚀性能的影响。结果表明,手工GMAW焊接的C-276合金,焊缝区析出碳化物第二相较多,晶间腐蚀倾向更大。     

Welding current and arc voltage control in a GMAW process using ARMarkov based MPC

A predictive functional controller based on ARMarkov model structure has been designed to control welding current and arc voltage in a GMAW process. The closed loop system performance is investigated through computer simulations and is compared by those achieved from implementing two commonly used controllers i.e. PI and feedback linearization based PID. The local stability of the closed loop system is analyzed in the presence of uncertainties in the linearized model of the process as well as the control parameters. Finally it is shown that the proposed controller performs like a PI controller along with a pre-filter compensator.     

基于Lyapunov指数刻画短路过渡GMAW的稳定性

基于不同焊接速度下短路过渡熔化极二氧化碳气体保护电弧焊的焊接电流时间序列,利用Takens相空间重构技术和Lyapunov指数的Wolf算法,分析评估了焊接系统的最大Lyapunov指数。结果表明,当焊接过程的稳定程度较高时,最大Lyapunov指数较小;而当系统处于不稳定状态、状态变动迅速时,最大Lyapunov指数相应较大;因此最大Lyapunov指数和焊接过程稳定性成负相关关系,可以将其作为刻画短路过渡熔化极二氧化碳气体保护电弧焊稳定性的一种新的量化指标。     

Investigate Weld Quality of Gas Metal Arc Welding Process Through Online Monitoring of Input Parameters

Gas metal arc welding (GMAW) is also referred as the metal inert gas (MIG) welding which is a process of welding done by the formation of an electric arc between the consumable wire electrode and the workpiece. Through the welding process, a continuous flow of inert gas is supplied, and it avoids the weld being subjected to react with at-mospheric air. The process can be automatic or semi-automatic where the main input parameters like current and the voltage can be direct and constant, respectively. Not only the current and voltage the welding quality depends on some more input parameters such as arc gap, velocity, and temperature. In this paper, we explain about a setup which is capable of real-time monitoring of input parameters mentioned above and selecting the best MIG welding parame-ters for the mild steel. The setup is composed of several sensors and microcontrollers for the collection and the measurement of the input parameters. The samples were categorized according to the federate and the voltage ad-justment of the selected welding machine. Then the final objective was to identify the samples of the weld with dif-ferent parameter changes which are monitored through the system. For the analysis, the samples were subjected to tensile and hardness tests, and microstructure tests to find the dependence of the input parameters which effect for the weld quality. Finally, the experimental results verified the effectiveness of the system for the selection of the quality weld.     

基于双NURBS曲线的叶轮叶片工业机器人GMAW增材制造

以双NURBS曲线获得的直纹面广泛存在于各行业复杂零件中,如何实现复杂直纹面的增材制造一直是增材制造领域中极为关心的问题。以双NURBS曲线描述叶片模型,进一步获得直纹面,采用优化工艺参数,以GMAW方法实现了叶轮叶片的增材制造,增材获得的叶片完整,成形良好,表明以GMAW工艺实现双NURBS曲线叶片增材制造是可行的。为叶片模型构建、复杂形状叶片的电弧增材制造提供了新方法,对复杂形状零件增材制造过程控制具有借鉴意义。     

Fluxless arc weld-brazing of aluminium alloy to steel

In this work, joining of aluminium alloy AA6061-T6 to Interstitial Free steel using pulsed gas metal arc welding process has been attempted. The effect of different surface conditions of steel (viz, galvanized, galvanealed and uncoated) and gap between the sheets on braze joint formation have been investigated. Galvanized steel surface showed good bead width, joint formation and lap shear strength compared to the other two combinations. Interface gap has not affected the wetting behaviour significantly but presence of a gap of 300 μm or so helped in escape of zinc vapour during the process there by avoiding formation of any crevice or macroporosity in the joint. Features and properties of the joint are characterized by metallography, fractography, energy dispersive spectroscopy (EDS) and lap shear tests. Load carrying capacity of Al-Galvanized steel was highest (222 N/mm of seam length) compared to other combinations, aided by better wetting due to presence of Zn on the surface and minimum porosity due to interfacial gap provided during brazing.     

基于新型控制法的逆变GMAW工艺特点

随着熔化极气体保护焊的应用与推广,那些以飞溅小和成形好为特点的通用型焊机常常不能适应新的环境和要求,如西气东输中的管道打底焊、集装箱的高速焊、汽车制造中的短焊缝焊接、角焊缝的尺寸控制和狭窄空间的熔深控制等,还有超薄板焊接、双脉冲焊、双丝高速焊、TIME高效焊和磁控MAG焊等,这些具有特殊功能的焊接方法,我们称为个性化焊接.这些个性化焊接方法均具有自己的工艺特点,并能完成一些特殊的焊接要求.可见这些个性化焊接方法必将成为GMAW推广应用的新的增长点.     

混合气体在熔化极气体保护焊中的应用

熔化极气体保护焊(GMAW)是焊接生产中常用的焊接方法之一.阐述了混合气体在熔化极气体保护焊中的应用现状,分析了保护气体成分的不同配比对熔化极气体保护焊的焊接工艺性能、焊接质量的影响.