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论文类型：期刊论文

发表时间：2009-11-01

发表刊物：OPTICS AND LASERS IN ENGINEERING

收录刊物：SCIE、EI、Scopus

卷号：47

期号：11

页面范围：1177-1182

ISSN号：0143-8166

关键字：Thermal-conduction welding; Keyhole welding; Low-power pulsed laser; Plasma behavior; Average peak power density

摘要：In the previous work, low-power laser/arc hybrid welding technique is used to weld magnesium alloy and high-quality weld joints are obtained. In order to make clear the interactions between low-power laser pulse and arc plasma, the effect of arc plasma on laser pulse is studied in this article. The result shows that the penetration of low-power laser welding with the assistance of TIC arc is more than two times deeper than that of laser welding alone and laser welding transforms from thermal-conduction mode to keyhole mode. The plasma behaviors and spectra during the welding process are studied, and the transition mechanism of laser-welding mode is analyzed in detail. It is also found that with the assistance of arc plasma, the threshold value of average power density to form keyhole welding for YAG laser is only 3.3 x 10(4) W/cm(2), and the average peak power density is 2.6 x 1 05 W/cm(2) in the present experiment. Moreover, the distribution of energy density during laser pulse is modulated to improve the formation and stability of laser keyholes. (C) 2009 Elsevier Ltd. All rights reserved.