Laser welding technological method for saddle-shaped aluminum alloy structure

Abstract

The invention discloses a laser welding technological method for a saddle-shaped aluminum alloy structure, and belongs to the technical field of welding. The method comprises the steps that a swing laser beam capable of achieving continuous outputting and uniform-speed movement is adopted for welding. In the welding process, the swing laser beam moves forwards along a shaft parallel to the welding direction. In the forward moving process, the swing laser beam swings with the shaft as a symmetrical shaft so as to from a movement path, and the movement path is composed of multiple paths shaped like a horizontal Arabic numeral 'eight'. By means of the method, laser welding joint internal cracks and air hole defects of the saddle-shaped aluminum alloy structure can be effectively avoided, a welding joint formed through welding is smooth in transition, and the welding joint comprehensive mechanical property is excellent.

Description

technical field [0001] The invention belongs to the field of welding technology and relates to a laser welding process method for a saddle-shaped aluminum alloy structure. Background technique [0002] With the increasing requirements for long range and high stealth capabilities of new aircraft, more and more special-shaped cross-section structures are used. With the continuous development of welding technology, sheet metal forming technology and thermoforming / superplastic forming technology, more and more riveted components and cast components are gradually replaced by welded components. Compared with riveted and cast components, welded components have the advantages of simple process, short production cycle, light weight and low cost. [0003] The large number of special-shaped cross-section structures has posed a great challenge to the original aerospace manufacturing process. The saddle-shaped aluminum alloy structure used in an aircraft product adopts a sheet-welding ...

AI Technical Summary

Problems solved by technology

Due to the complex welding structure, long welding process and long weld length, the problems existing in the welding process of the saddle-shaped aluminum alloy structure include: poor forming accuracy of the skin components, welding deformation makes it difficult to assemble subsequent parts, and the assembly accuracy is difficult to meet the welding requirements. Assembly requirements; the overall length of the weld is long, the structure is asymmetric, and the deformation after welding is more serious; the problem of pores in the aluminum alloy weld is more prominent; the welding cycle of the fuel tank is long, and it is difficult to clean the weld after the pickling time exceeds the standard

Among them, the heat input of argon arc welding is high, and the deformation of structural parts after welding is serious. Compared with high-energy beam welding, the welding speed is slow and the efficiency is low; electron beam welding has the advantages of fast welding speed, small welding heat input, and high internal quality of the weld. Electron beam welding must be carried out in a vacuum environment, it is difficult to automate, the welding efficiency is low, and the cost is high, and the economy is poor; laser welding has high energy density, fast welding speed, large aspect ratio, strong adaptability, and easy automation. Advantages, can meet the complex and diverse needs of future aerospace product structures

However, at present, there are few studies on laser welding of special-shaped cross-section structures, especially lightweight sheet-welding structures, and there is a lack of laser welding methods to control defects such as cracks and pores in laser welds of aluminum alloy structures.

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