Welding method of 7-series aluminum alloy coated thin plate for aviation

Abstract

A welding method of a 7-series aluminum alloy coated thin plate for aviation comprises the following steps that 1, after a coating material and a cast ingot are attached, the distance between the periphery of the coating material and the edge of the cast ingot is 20-30 mm, fixing and welding are conducted in a bolt fastening manner every 1000-1500 mm in the length direction, and a material for welding adopts 7075-F-state aluminum alloy; 2, the composite cast ingot obtained in the step 1 is heated and hot-rolled; and 3, the plate with the thickness ranging from 7.0 mm to 8.0 mm through hot rolling is subjected to three times of cold rolling till the thickness ranges from 1.6 mm to 3.25 mm. According to the method, a spot welding mode is adopted, the plate must be packaged through steel strip in the transferring process so as to avoid the falling risk, however, in the ingot soaking process, due to the fact that the temperature is high, the steel strip is prone to leaving traces on the surface, and due to the fact that the temperature of the composite ingot is reduced in the steel strip shearing process, the two factors can cause aluminum sticking of a roller in the subsequent rolling process, the problem of rolling black lines is formed, the surface quality is unqualified, and the yield of products is reduced.

Description

technical field [0001] The invention belongs to the field of aviation aluminum alloy clad thin plates, in particular to a welding method for aviation 7-series aluminum clad thin plates. Background technique [0002] The 7-series aluminum alloy clad sheet material is used as an aircraft skin panel material due to its excellent corrosion resistance, high strength, and low specific gravity. As the main skin material of aviation aircraft, it is mainly imported from abroad. At present, there are still some technical difficulties in the development of this clad thin plate material, such as its uneven cladding, and the unoptimized cladding welding method will easily lead to open welding of solder joints and cause the risk of cladding falling off. . At present, there is no mature technology in China to prepare related cladding sheet materials. With the help of the national new material application demonstration platform (aviation materials) related production line construction pr...

AI Technical Summary

Problems solved by technology

In the development process of 7075 aluminum alloy clad thin plate, there are problems such as unreliable ingot welding, poor surface quality, and difficult control of cladding thickness uniformity, which makes its comprehensive performance fail to meet the technical design requirements and cannot meet the skin material of large aircraft localized alternative

[0004] The 7075 aluminum alloy belongs to the Al-Zn-Mg-Cu series. It is a heat-treatable and strengthened aluminum alloy. It has the advantages of high strength, low specific gravity and high fatigue performance. Corrosion resistance is poor, so it is necessary to cover the surface with a layer of pure aluminum plate with high corrosion resistance. In this way, the strength of 7075 aluminum alloy is retained and its corrosion resistance is increased. Therefore, as a skin plate material, it is widely used. Favored by the world aviation industry

However, during the transfer process, the steel strip must be packed to avoid the risk of falling off. However, during the soaking process of the ingot, due to the high temperature of the solution, the steel strip is easy to leave marks on the surface, and it is also caused by the cutting of the steel strip. The temperature of the composite ingot is lowered, and both factors may cause the roll to stick to aluminum in the subsequent rolling process, thereby forming the rolling black line problem, resulting in unqualified surface quality and lower product yield

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