Laser welding plume control and molten bath protection method and device

Abstract

The invention relates to a laser welding plume control and molten bath protection method and device, and belongs to the field of welding. Laser beams generated by a laser device are focused to act on a workpiece, a deep molten small hole and a molten bath are formed; an inner pipe of a double-layer spraying nozzle is placed above a small hole opening and is connected with an air exhauster to enable a stable negative pressure state to be formed at a zone of the small hole opening, and plume sprayed out from the hole quickly escapes out through air exhausting of the inner pipe; and an outer pipe of the double-layer spraying nozzle is arranged above the molten bath, and protective gas is led in for protecting the welding molten bath. According to the laser welding, the negative pressure in the spraying nozzle controls the plume, and the protective gas is led into the outer pipe for protecting the welding molten bath. By means of the local negative pressure environment above the small hole opening, the absorbing and scattering functions of the plume on lasers can be thoroughly avoided, a better transmission channel is provided with the laser beams, the lasers are sufficiently focused on the welding workpiece, and the laser energy using rate is greatly improved; according to the inner pipe of the spraying nozzle, after disturbance of the plume on protective gas flow is removed, the welding molten bath can be better protected by the outer pipe of the spraying nozzle.

Description

technical field [0001] The invention relates to a welding method, which belongs to the technical field of laser material processing, in particular to a laser welding plume control and molten pool protection method and device. Background technique [0002] Laser welding has significant advantages such as high energy density, high welding efficiency, small heat input, small welding deformation, and no direct contact during welding. It is considered to be one of the most advanced material joining technologies in the 21st century and has been widely used. . In recent years, solid-state lasers (such as fiber lasers, disk lasers, and Nd:YAG lasers) have made great progress, and the advantages of such lasers in material processing have become more and more obvious. Taking fiber laser as an example, it has comprehensive advantages such as high electro-optic conversion efficiency, high output power, high beam quality, high processing flexibility, and low operating cost, providing a ...

AI Technical Summary

Problems solved by technology

Laser arc hybrid welding can burn off the plume and eliminate the negative effect of the plume through the arc, but this method also reduces the flexibility of laser welding, increases the heat input and expands the heat action zone, which will lead to a decrease in the performance of the welded joint and workpiece thermal deformation increase and other issues

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