【作者】 高莹；

【导师】 李桓；

【作者基本信息】 天津大学 ， 材料加工工程， 2010， 博士

【摘要】 由于激光与电弧之间的相互作用机理的研究对进一步开发激光复合焊工艺具有重要意义,本文首先搭建了激光+脉冲MIG旁轴复合焊系统,以此热源为对象,对激光与脉冲MIG电弧的相互作用机理进行研究。由于激光能量集中,激光对电弧的影响不可能均匀分布,传统的研究方法如电信号采样、高速摄像法都只能判断电弧总体的特征,不能对电弧不同区域进行诊断,为了诊断电弧不同区域在复合前后的变化情况,本文提出一种对电弧光谱辐射进行定“点”采集的策略。为实现该策略,本文开发了小孔探测器,此设备使研究激光与脉冲MIG电弧相互作用的机理成为可能。由于脉冲MIG电弧呈周期性变化,为了精确采集不同状态电弧在激光复合前后的相关信号,本文开发了可以实现电信号、高速摄像信号、光谱信号同步采集的多信息同步采集系统。同步采集系统可以实现三种信号的同步采集,对研究激光与脉冲MIG电弧的复合机理提供了试验条件。本文利用该系统与小孔探测器对激光复合前后的脉冲MIG电弧区进行了采集,得到了同步的电弧信息。通过对这些信息的分析,本文构建了基值电弧与峰值电弧在复合前后的光谱辐射强度的空间分布图,并且采用Boltzmann图法计算了复合前后电弧的电子温度,并建立电子温度的的空间分布。通过对试验数据进行研究,发现在本文所建坐标系峰值复合电弧在0≤X≤2,0≤Y<2的区域内,基值复合电弧在0≤X≤1,0≤Y≤1的区域内,出现了辐射强度与电子温度增大现象。根据以上结论,本文构建了复合电弧的能量分布模型,模型显示激光复合后电弧出现一个等离子体能量增强区,并结合本试验数据提出了三种等离子体能量增强区的形成机理。更多还原

【Abstract】 Because of the interaction mechanism between laser and arc for the further development of laser hybrid welding was important. Laser + pulsed MIG paraxial hybrid welding system has been built in this paper,By research on this hybrid heat source, the interaction mechanisms between laser and pulse MIG arc could be obtained.As the concentration of laser energy, laser effects on the arc could not distributed throughout the whole arc. Traditional research methods, such as acquisition of electrical signals, high-speed photography method could determine the general characteristics of arc,but different regions of the arc could not be diagnosed by these traditional methods. In order to diagnose different regions of arc before and after laser hybrid. A "point" acquisition strategy has been presented in this paper. Spectral information of different point in arc area could be collected by this strategy. To achieve this strategy, a small hole detector has been developed in this paper. This device made it possible for the study on interaction mechanism between laser and pulse MIG arc.As the pulsed MIG arc varied periodically,In order to accurately capture the relevant signals of different states arc before and after laser hybrid. Synchronous multi-information collection system has been built in this paper. The electrical signals, high-speed photographs, spectral signals could be collected synchronously by using this system. A guarantee for the research on interaction mechanism between laser and arc has been provided by this system.In this paper, the synchronous multi-information collection system and the hole detector have been used to collect informations of the pulse MIG arc before and after laser hybrid. The synchronization informations of arc have been obtained, through the analysis of thes informations, spatial spectral radiation distributions of base and peak arc before and after laser hybrid have been constructed in this paper. Boltzmann diagram method has been used to calculate the electron temperature of the arc before and after laser hybrid. The spatial distribution of electron temperature has been built.Through the research on the experimental data, the paper found that in the coordinate system which has been built in this paper, the radiation intensity and electron temperature of the peak hybrid arc increased in 0≤X≤2,0≤Y <2 region, radiation intensity and electron temperature of the base hybrid arc increased in 0≤X ≤1,0≤Y≤1 region. An energy distribution model of the hybrid arc has been built in this paper. This model shown that the arc plasma energy increased in a region of laser hybrid arc. Based on these conclusions, the formation mechanisms of the Energy Enhancement region have been discussed. Three formation mechanisms have been proposed.更多还原