کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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735477 | 893615 | 2006 | 13 صفحه PDF | دانلود رایگان |
In laser welding, the shielding gas is commonly used to stabilize the welding process, to improve welded joints features and to protect the welded seam against oxidization. Besides the type of shielding gas used, the nozzle parameters play an essential role. In fact, the chemical composition of the shielding gas and the flow geometry are key factors limiting the size of the plasma plume and its contamination by the surrounding atmosphere, and affecting the final quality of the welded joints.In this work, we present an experimental study on the complex physical phenomena occurring during the interaction between the plasma plume, the laser beam and the shielding gas by using an in-process spectroscopic investigation of the plasma plume characteristics under different operating conditions. A correlation was found between the spectral features and the formation of oxide layers on the surface of the welding seam, caused by defective gas shielding and by the vaporization of alloying elements. Experimental results have given useful indications for the development of innovative welding nozzle for application in laser welding of aluminium alloys.
Journal: Optics and Lasers in Engineering - Volume 44, Issue 10, October 2006, Pages 1039–1051