Papers by Keyword: Laser Penetration Welding

Abstract: According to the calculation model of the keyhole porfile[1], the 3D point cloud data is calculated. Then, the paper establishes a physical model of the keyhole in the laser welding by using the 3D reverse technology. The adaptive mesh generation of the model is processed by the independent development software. Finally this paper establishes a mathematical model of the temperature field in the laser welding, which considers the factor of the welding velocity. A more accurate temperature field is obtained by using the laser welding solver which is a secondary development of OpenFOAM, adding the Guass surface source and the keyhole volume source, and setting the boundary condition of convection and radiation. The result provides more accurate bases for the welding stress field.

Abstract: The distribution and appearance characteristics of porosities in laser penetrated weld of aluminum alloy were observed, and the formation mechanisms of porosities were analyzed in detail, and the influences of twin spot laser energy distribution on porosities were investigated. It showed that there are two kinds of porosities, metallurgical and technologic porosities, in laser penetrated weld of aluminum alloy. The formation of metallurgical porosities is related to the separation, congregation and incorporation of hydrogen in the weld pool, while instantaneous instability of the keyhole is an essential reason for the occurrence of technologic porosities. Twin spot laser energy distribution can enlarge diameters of the opening and the root of the keyhole, improve fluctuating conditions of the wall of the keyhole, increase stability of the keyhole, and consequently decrease technologic porosities in number, but it has no obvious influence on metallurgical porosities.