Hollow structure forming method

Abstract

The invention relates to a hollow structure forming method. The hollow structure forming method comprises the steps that a welding stop agent is coated between two or more core boards, the core boardsare laminated, heating is performed to reach diffusing connection temperature, and diffusing connection is completed through pressurizing; laminated face boards are placed on two sides of a core board assembly formed after diffusing connection, the peripheries of laminated blank assemblies are soldered and sealed, and an inner layer air channel and an outer layer air channel are reserved; the laminated blank assemblies are put in a super-plastic forming mold, heating is performed to reach the predetermined temperature lower than the diffusing connection temperature, and air introduction for pressurizing is performed through the outer layer air channel, so that the outer-layer face boards are stressed to outward extend and deform and complete super-plastic forming; after super-plastic forming of the face boards, air is discharged for pressure relief through the outer layer air channel, and then air introduction for pressurizing is performed through the outer layer air channel, so thatthe core boards are stressed to outward extend and deform and complete super-plastic forming; after super-plastic forming of the core boards, heating is performed to reach the diffusing connection temperature, heat preservation and pressure maintaining are performed, so that diffusing connection between the outer-layer face boards and the core boards is achieved.

Description

Technical field [0001] The invention relates to the technical field of superplastic forming / diffusion bonding, in particular to a hollow structure forming method using superplastic forming / diffusion bonding technology. Background technique [0002] The superplastic forming / diffusion joining technology has the advantages of near net shape, good integrity, high rigidity, and large design freedom in the manufacture of hollow structural parts. It has a wide range of applications in aviation, aerospace and other fields. According to the number of layers required for structural manufacturing, the process structure can be divided into single-layer, two-layer, three-layer and four-layer structures, among which two-layer and four-layer structures are the most widely used. The rigidity and strength of the four-layer structure are more prominent, so it has become a choice in many lightweight structural designs, such as pelvic fins, rectifier blades, and rudder wing surfaces. For the four-l...

AI Technical Summary

Problems solved by technology

[0003] At present, the most direct way to control the groove of the four-layer structure is to increase the thickness of the skin panel, and remove the excess thickness by mechanical processing or chemical milling after the formation is complete. This method not only wastes materials but also increases the process, resulting in production cycle. long

Another method is to use the same thickness of the sheet metal to prevent grooves by back pressure forming. This method is suitable for parts with large cavity sizes, but the process control is complicated. For parts with small cavity sizes or complex profiles The parts still cannot eliminate surface groove defects very well

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