Method for conducting laser modification welding on titanium alloy weld joint through wave absorbing coating

Abstract

The invention provides a method for conducting laser modification welding on a titanium alloy weld joint through a wave absorbing coating. The method includes the steps that firstly, the weld joint is preprocessed; secondly, the weld joint is coated with the wave absorbing coating; thirdly, the weld joint is scanned through a defocusing laser spot, and the laser modification welding operation conducted on titanium alloy is completed, wherein the wave absorbing coating is prepared from, by mass, 40-70% of NaF2, 10-20% of Y2O3, 10-20% of Cr2O3 and 10-20% of La2O3. By means of the technical scheme, the undercut defects on the surface of the titanium alloy weld joint can be effectively eliminated, and residual stress of welding can be remarkably reduced.

Description

technical field [0001] The invention relates to a method for performing laser modification welding on a titanium alloy welding seam by using a wave-absorbing coating, and belongs to the technical field of laser processing. Background technique [0002] Compared with conventional welding methods, laser welding has high energy density, concentrated heating, small thermal damage to materials, large weld depth-to-width ratio, low residual stress in welded joints, and high welding precision, which can significantly reduce post-weld processing. It is easy to be integrated, automated, and flexible. It is a high-speed, high-precision, and efficient high-energy beam welding method. The quality of the welded joints is comparable to that of electron beam welding, but it does not require a vacuum environment and does not generate X-rays. It is one of the advanced manufacturing technologies. Laser welding between titanium alloy skin structure parts is commonly used in engineering applica...

AI Technical Summary

Problems solved by technology

The current research can realize the optimization of the shape and performance of the weld seam, but it cannot fundamentally eliminate the undercut phenomenon of the weld seam

[0005] The existing laser decoration welding adopts the defocusing method to directly perform secondary remelting on the weld surface. Although the undercut defect on the weld surface can be eliminated, due to the secondary energy effect brought by the decoration welding, the workpiece after the decoration welding is severely damaged. Deformation, large welding residual stress

At the same time, due to the secondary remelting of the weld surface, impurities on the weld surface (such as welding fumes, oxides, etc.) are likely to cause a large number of micropores (<0.1mm), which will adversely affect the performance

Images