Superplastic forming (SPF)/diffusion bonding (DB) forming method of titanium alloy cylindrical three-layer structure

Abstract

The invention belongs to a sheet-metal forming technology, and relates to a superplastic forming (SPF) / diffusion bonding (DB) forming method of a titanium alloy cylindrical three-layer structure. A novel blank structural form and a blank production method are adopted, the requirements on coating welding stopping agent and positioning a cylinder on a three-layer structure can be met, and a hot isostatic pressure DB and cylinder SPF step-by-step formation method is adopted for the cylinder blank, so that the technical difficulty and complexity can be reduced, and the structural flexibility can be improved. A partition ring is creatively additionally arranged among the cylinders, the dropping of the welding stopping agent, caused by the collision of the cylinders, can be avoided, an air inlet passage and an exhaust passage are directly machined and formed on the blank, no air passage needs to be machined on a mold, and the structural complexity of a tool can be reduced. The SPF / DB formation of the titanium alloy cylindrical three-layer structure can be stably and reliably realized, and the formation quality and the technological stability can be improved. The SPF / DB technological method is enlarged from the formation of a flat sandwich structure to the formation of the cylindrical rotation sandwich structure, so that the application field of the process can be enlarged, and good economic and technical benefit can be realized.

Description

technical field [0001] The invention belongs to sheet metal forming technology, and relates to a superplastic forming / diffusion connection forming method of a titanium alloy cylindrical three-layer structure. Background technique [0002] As a typical structural form of the missile inlet and shell, the sandwich structure of the cylinder requires that the components not only meet the requirements of coaxiality, roundness and other external dimension accuracy requirements, but also need to meet special performance requirements such as light weight, high strength, sealing and heat insulation. , the manufacturing process is complicated and difficult. The traditional manufacturing method of the sandwich structure of the cylinder is welding and riveting of the skin skeleton, such as figure 1 shown. First, the titanium alloy internal skeleton is formed by machining or casting, and then the skeleton and the skin are welded and riveted into a whole to form a hollow sandwich structu...

AI Technical Summary

Problems solved by technology

For some rotary sandwich structures such as cylinders, the traditional flat multi-layer structure SPF / DB forming process has been unable to realize

Especially for the sandwich structure of the cylinder, the traditional manufacturing method is the welding and riveting of the skin skeleton. The thickness of the casting skeleton is large, the structure is overweight, and the skin and skeleton are prone to deformation during the welding and riveting process, making it difficult to guarantee the accuracy of the external dimensions of the components. , poor integrity and other shortcomings

However, the traditional SPF / DB forming process can only form flat multi-layer structures, and cannot realize the forming of some rotary sandwich structures such as cylinders.

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