Forming method of superplastic forming/diffusion connecting four-layer structure of grid with variable depth-width ratio

Abstract

The invention relates to a forming method of a superplastic forming / diffusion connecting four-layer structure of a grid with variable depth-width ratio, and belongs to the technical field of surface wrinkle prevention, and the surface of the four-layer structure formed by virtue of the method is flat and winkle-free. According to the method, in the process of forming a core board into a grid, the grids with different depth-width ratios are different in expanding start time, i.e., the grid with higher depth-width ratio is formed before the grid with lower depth-width ratio, and the grids with approximate depth-width ratios are approximate in expanding start time, so that the contact start time of each grid and a panel at the position of the grid is approximate; meanwhile, in the grid forming process, the air pressure between the panel and the core board is always kept high, so that the part, which is contacted with the panel, of the grid is not subjected to diffusion connection immediately in the expanding process; due to the effects of two aspects, the problem that the panel draws back along with deformation of the core board in a grid continuous expanding process can be prevented, and thus wrinkles are prevented from occurring.

Description

technical field [0001] The invention relates to a forming method of a superplastic forming / diffusion connection four-layer structure with variable aspect ratio grids. The surface of the four-layer structure formed by the method is smooth and wrinkle-free, and belongs to the technical field of surface wrinkle prevention. Background technique [0002] The superplastic forming / diffusion bonding process is usually applied to the forming of sheet metal. This process can be used to form four-layer thin-walled mesh parts. This structure has the advantages of thin wall and light weight, and can be applied to the manufacture of aerospace vehicle rudders Manufacture of wing parts to meet the weight reduction requirements of the structure. [0003] The process is achieved by superplastic forming and local diffusion joining of four-layer sheet metal blanks using air pressure in the part mold cavity at high temperature. Among the four-layer sheets, the outer one is the panel, which fina...

AI Technical Summary

Problems solved by technology

[0006] The purpose of the present invention is to solve the problem of surface wrinkle defects that often occur in the four-layer structure with variable aspect ratio grids in the superplastic forming / diffusion bonding process. Forming method of superplastic forming / diffusion bonding four-layer structure

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