Apparatus and method for confinement and suppression of photoinduced plasma in high-power laser deep penetration welding

Abstract

The invention discloses a device for restraining a laser-induced plasma in high power laser deep penetration welding. The device comprises a cooling copper block, a floating gas curtain and a positioning part. The cooling copper block comprises two axisymmetric parts, an arc-shaped surface is arranged towards a weld joint side, and the cooling copper block is cooled relying on circulating water; the floating gas curtain is arranged on the bottom of the cooling copper block and uniformly sprays inert gas with a certain flow; the positioning part is used for fixing a restraining structure on a laser welding operating head and keeping the relative positions of the restraining structure and the laser welding operating head fixed. Meanwhile, the invention discloses a method for restraining the laser-induced plasma in the high power laser deep penetration welding. According to the device and the method, expansion of the laser-induced plasma in the three-dimensional direction is restrained in a high power laser welding process, the amplitude of fluctuation of the laser-induced plasma is reduced, thus a stable welding process and good formation of weld joints are obtained, and the device can be widely applied to the high power laser deep penetration welding field.

Description

technical field [0001] The invention relates to the technical field of laser welding, in particular to a device and method for suppressing photoinduced plasma during laser deep penetration welding. Background technique [0002] Photoinduced plasma is an important physical phenomenon in the process of high-power laser deep penetration welding. If the plasma is not suppressed or suppressed insufficiently, it will seriously affect the welding process. At present, the control methods of photoinduced plasma are as follows: [0003] 1. The auxiliary gas purges the laser incident place through the coaxial or side nozzle. This method has a certain purging effect, but usually helium is used as the auxiliary gas, which is very expensive. In order to improve the purging effect of the auxiliary gas, there are literatures and patents on the design and optimization of the nozzle structure, which has a certain effect on solid-state laser and low-power carbon dioxide laser welding, but the ...

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Problems solved by technology

The effect of this method is not very significant, although relevant literature has been involved, but no detailed introduction and in-depth analysis have been carried out.

[0005] 3. Use the device to make the welding area an approximate vacuum environment, and the photoinduced plasma diffuses and disappears rapidly in the vacuum environment, but this method is difficult to implement in practical applications, which is greatly limited

[0006] It can be seen that there is currently no effective suppression method for the photoinduced plasma in the high-power laser deep penetration welding process, it is difficult to ensure the stability of the welding process, and ultimately it is impossible to obtain uniform and consistent ideal penetration

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