Detection of defects in laser welding of AZ31B magnesium alloy in zero-gap lap joint configuration by a real-time spectroscopic analysis.
Detection of defects in laser welding of AZ31B magnesium alloy in zero-gap lap joint configuration by a real-time spectroscopic analysis.
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DOI：
10.1016/j.optlaseng.2013.11.015
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发表时间：
2014-05-01
影响因子：
4.6
通讯作者：
Kovacevic, Radovan
中科院分区：
文献类型：
--
作者：
Harooni, Masoud;Carlson, Blair;Kovacevic, Radovan
研究了镁板搭接接头表面存在的表面氧化层对熔池小孔动力学和焊道质量的影响。据观察，通过去除搭接接头搭接表面的氧化层，可以在激光焊接过程中实现高质量的焊接。然而，氧化层的存在会在两个重叠板材的界面处形成气孔，从而降低焊接质量。本文的目的是确定焊缝完整性与激光与材料之间相互作用之间的相关性。应用光谱传感器来检测零间隙搭接接头配置中的 AZ31B 镁合金激光焊接过程中等离子羽流发出的光谱。根据检测到的光谱，应用玻尔兹曼图法计算电子温度，并研究孔隙形成与光谱信号之间的相关性。激光熔池和小孔状况由高速电荷耦合器件（CCD）相机实时监控。使用绿色激光作为照明源，以检测氧化层对熔池动态行为的影响。结果表明，检测到的光谱和焊接缺陷对于实时监测镁合金激光焊接过程中的焊接质量具有有意义的相关性。 (C) 2013 Elsevier Ltd. 保留所有权利。
The effect of surface oxide layer existing at the lap-joint faying surface of magnesium sheets is investigated on the keyhole dynamics of the weld pool and weld bead qualities. It is observed that by removing the oxide layer from the faying surface of the lap joint, a high quality weld can be achieved in the laser welding process. However, the presence of an oxide layer deteriorates the quality of the weld by forming pores at the interface of the two overlapped sheets. The purpose of this paper is to identify the correlation between the integrity of the weld and the interaction between the laser and material. A spectroscopy sensor was applied to detect the spectra emitted from a plasma plume during the laser welding of AZ31B magnesium alloy in a zero-gap lap joint configuration. The electron temperature was calculated by applying a Boltzmann plot method based on the detected spectra, and the correlation between the pore formation and the spectral signals was studied. The laser molten pool and the keyhole condition were monitored in real-time by a high speed charge-coupled device (CCD) camera. A green laser was used as an illumination source in order to detect the influence of the oxide layer on the dynamic behavior of the molten pool. Results revealed that the detected spectrum and weld defects had a meaningful correlation for real-time monitoring of the weld quality during laser welding of magnesium alloys. (C) 2013 Elsevier Ltd. All rights reserved.