共查询到17条相似文献,搜索用时 187 毫秒
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采用高速摄影与电信号小波分析研究了双丝共熔池熔化极气体保护焊(TCG-MAW)脉冲频率变化对焊接过程熔滴过渡方式和频率及焊缝成形的影响.结果表明,在文中焊接工艺参数下,脉冲频率较高(140 Hz)时,前丝熔滴过渡方式为射流过渡,后丝为射滴过渡;脉冲频率较低(40 Hz)时,前丝、后丝熔滴过渡方式均为射滴过渡;脉冲频率中等(60~100 Hz)时,前丝、后丝熔滴过渡方式均为射流过渡;脉冲频率在40~140 Hz变化时,前丝、后丝熔滴过渡基本上表现为一脉一滴形式.当脉冲频率大约在60~100 Hz变化时,焊缝成形较好. 相似文献
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利用高速摄像、电信号采集系统记录了Fornius CMT TWIN设备四种协同模式下焊接5083铝合金时双丝焊接电流电压波形和熔滴过渡过程,并分析了电流电压波形的特征、弧长变化规律和熔滴过渡方式。结果表明,双脉冲模式时,前后丝脉冲段时间一致,脉冲频率主要由维弧段时间决定,熔滴过渡以射滴过渡为主;双CMT模式时,前丝由较长时间的类脉冲波段和较短时间的类CMT波段组成,熔滴过渡分别为射流过渡和短路过渡,后丝完全以CMT方式过渡,熔滴过渡以短路过渡为主;前丝脉冲+后丝CMT或前丝CMT+后丝脉冲混合模式中,CMT波形未发生变化,而脉冲波形的电流和电压产生波动。电流电压变化和熔滴过渡是造成弧长变化的重要影响因素。前丝脉冲模式时焊缝熔深和熔宽大,而后丝CMT模式时焊缝余高大。 相似文献
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将脉冲等离子电弧与MIG电弧同轴复合,期望利用等离子弧脉冲峰值电流产生的高速等离子射流冲击熔滴和熔池,促进熔滴过渡,同时增加焊缝熔深。开发了一套高速视觉与电信号精确同步的焊接数据采集系统,对脉冲等离子-MIG复合焊熔滴过渡行为进行研究。研究发现将等离子电流调制成脉冲波形,等离子弧对工件总体热输入下降,等离子峰值电流产生的等离子流力可以有效促进熔滴过渡。在此基础上深入分析了等离子脉冲峰值电流、脉冲宽度及熔滴在等离子弧过渡位置等参数对熔滴过渡的影响,获得了脉冲等离子-MIG复合焊一脉一滴过渡的工艺参数窗口。 相似文献
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采用高速摄影技术对三电弧双丝电弧焊的熔滴过渡和焊接飞溅进行观察,分析金属型药芯焊丝在M弧电流变化时熔滴过渡的类型及飞溅产生的原因.结果表明,M弧电流为170 A时熔滴过渡形式有排斥过渡、颗粒过渡及细颗粒过渡,熔滴过渡不稳定.M弧电流为210 A时前丝和后丝熔滴过渡为大熔滴排斥过渡,三电弧同时出现,熔滴过渡稳定.M弧电流为260 A时前丝熔滴过渡为细颗粒过渡,后丝熔滴过渡为颗粒过渡,熔滴过渡较稳定.焊接飞溅产生的原因主要是脉冲切换改变了电弧力、斑点力及等离子流力,打破了原来的力系平衡. 相似文献
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1. 佳木斯大学 材料科学与工程学院,佳木斯 154007; 2. 深圳瑞凌实业股份有限公司,深圳 163000; 3. 哈尔滨工业大学 先进焊接与连接国家重点实验室,哈尔滨 150001
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采用高速摄影技术对三电弧双丝电弧焊的熔滴过渡和焊接飞溅进行观察,分析金属型药芯焊丝在M弧电流变化时熔滴过渡的类型及飞溅产生的原因. 结果表明,M弧电流为170 A时熔滴过渡形式有排斥过渡、颗粒过渡及细颗粒过渡,熔滴过渡不稳定. M弧电流为210 A时前丝和后丝熔滴过渡为大熔滴排斥过渡,三电弧同时出现,熔滴过渡稳定. M弧电流为260 A时前丝熔滴过渡为细颗粒过渡,后丝熔滴过渡为颗粒过渡,熔滴过渡较稳定. 焊接飞溅产生的原因主要是脉冲切换改变了电弧力、斑点力及等离子流力,打破了原来的力系平衡. 相似文献
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建立了双丝M IG焊工艺试验研究平台,该试验平台主要由Tandem型双丝焊系统、信号采集系统、高速摄像(摄影)系统以及脉冲控制系统等部分组成.在此基础上研究了脉冲电压峰值对双丝脉冲M IG焊熔滴过渡及焊缝成形的影响.结果表明,前丝脉冲峰值电压对熔滴过渡的影响比较显著.前丝脉冲峰值电压较低时,熔滴过渡形式为射滴过渡,前丝脉冲峰值电压较高时熔滴过渡形式为一脉一滴过渡形式,过大的前丝脉冲峰值电压的熔滴过渡形式为大滴过渡.前丝脉冲峰值电压越高,焊缝熔宽和熔深越大,过高的前丝脉冲峰值电压会导致焊缝表面质量恶化. 相似文献
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In view of the unstable welding process of Tri-Arc DE, surfacing test with Q235 steel plate was completed with the help of the self-built high-speed camera and waveform synchronous acquisition system using the Tri-Arc DE technology. The effects of pulsed M-Arc frequency on Tri-Arc DE droplet transfer and weld formation were analyzed. The results show that while the gradual increase of pulse frequency, the droplet transfer frequency gradually decreases, which is followed by several drops per pulse, one drop per pulse, and one drop within several pulses. The most ideal transfer form is one drop per pulse, of which the welding process is the most stable, and the quality of weld formation is the most satisfied. 相似文献
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脉冲熔化极气体保护焊(GMAW-P)熔滴过渡形式对焊接质量有着重要的影响,同时脉冲参数是影响GMAW-P熔滴过渡行为的主要参数.利用高速数字摄像技术,记录熔滴过渡过程,同时采集焊接过程的电流、电压信号,并将各个信息传输到PC机中,实现数据的保存.综合分析熔滴过渡图片与对应的电信号的关系,提取了GMAW-P熔滴过渡过程特征电信号.通过统计分析建立了GMAW-P熔滴过渡逻辑回归模型.结果表明,此模型预测熔滴过渡的正确率达93%,为实现一脉一滴最佳脉冲熔滴过渡形式闭环控制开辟了新的途径.Abstract: Metal droplet transfer mode which is influenced by the pulse parameters such as pulse current ( I_p ) , pulse time ( t_p ) , base current ( I_b ) and pulse frequency (f) has play an important role in the weld quality. An experimental system based on the Lab VIEW virtual instrument and high speed photography technology was developed to sample the transient electrical parameters and record the images of droplet transfer process simultaneously. A transition voltage U_(dd) in the pulse voltage drop edge of electrical waveform was discovered according to analysis of synchronous electric and image signals. The relationship between the metal transfer mode and the slope of the transition voltage was proposed. The result of experiments shows that the model can be used in closed-loop controlling of one droplet per pulse transfer mode and also can help for optimizing the welding parameters. 相似文献
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基于流体力学和电磁学理论,通过添加超声振动和声辐射力条件,建立超声辅助的熔化极惰性气体保护焊(超声-MIG)熔滴过渡行为的数学模型。利用FLUNET软件模拟在不同焊接电流和超声振幅下熔滴长大、变形和脱落的过程。模拟结果显示,熔滴的轮廓变化和脱落时间与相关试验结果吻合较好;与常规MIG焊相比,在小电流条件下超声-MIG焊熔滴的脱落尺寸相对更小且过渡频率更快,而在大电流的条件下超声-MIG焊熔滴脱落时间和尺寸变化不太明显;超声-MIG焊熔滴脱落时间受超声振幅的影响,超声振幅的增大会在一定程度上使熔滴过渡周期缩短。 相似文献
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B Wichtowski 《Welding International》2013,27(3):180-184
Summary Undercut and/or humping are generated when the arc length in high-speed pulsed MAG welding is too high, and spatter is generated if it is too low. Refinement of the droplets from the wire and simultaneous maintenance of one droplet transfer per pulse avoid short-circuiting in a short arc and enable spatter and highspeed/high-efficiency welding to be rendered compatible with each other. The requirements are to maintain a stable droplet shape during one droplet transfer per pulse, to maximise the welding speed limit without spatter generation, and to develop a technology for arc length shortening at the limit of short-circuiting by wire droplet refinement as objectives basically centred on pulsed MAG welding. This paper describes an investigation of the factors controlling droplet transfer through a division being made into the driving force imparted to the droplets and the deformability of the weld metal receiving this force as well as a method of droplet refinement based on resolution of these aspects. Through the simple rectangular wave pulse of a high peak current being set for a short time using an inverter-type pulsed power source at a constant wire diameter to increase the electromagnetic pinch force, one droplet transfer per pulse is possible on condition that the droplet volume is reduced by around 30% as compared with that obtained using a conventional power source with a chopping transistor on the secondary side. To increase the droplet deformability, the wire composition can be changed to achieve one droplet transfer per pulse on condition that the droplet volume is reduced by 20%. These droplets also show the same surface tension as conventional droplets as well as a lower viscosity coefficient. Through a combination of a pulsed current waveform and improved wire properties, the droplet volume can be reduced to around one half that of conventional droplets. The critical speed of spatter- and defect-free welding is then increased as an improvement immediately applicable on an actual automotive mass production line. 相似文献