Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5350914 | Applied Surface Science | 2015 | 24 Pages |
Abstract
To understand the laser-matter interaction in fiber laser welding of aluminum alloys, the effects of laser power on the characteristics of fiber laser induced plasma plume were studied by emission spectroscopic analysis firstly. The plasma characteristic parameters including electron temperature, electron density, ionization degree, and inverse bremsstrahlung linear absorption coefficient were computed according to the spectral data. It was found that the laser power of 5Â kW is a turning point. After the laser power reaches 5Â kW, the plume changes from a metal vapor dominated weakly ionized plasma to a strongly ionized plasma. The corresponding phenomena are the dramatic increase of the value of characteristic parameters and the appearance of strong plasma shielding effect. The calculation of effective laser power density demonstrated that the plasma shielding effect is dominated by inverse bremsstrahlung absorption. The finding suggested the plasma shielding effect must be considered in fiber laser welding of aluminum alloys, rather than is ignored as claimed in previous view.
Related Topics
Physical Sciences and Engineering
Chemistry
Physical and Theoretical Chemistry
Authors
Ming Gao, Cong Chen, Ming Hu, Lianbo Guo, Zemin Wang, Xiaoyan Zeng,