Cryogenic forming method for large-size aluminum alloy tailored blank component

Abstract

The invention provides a cryogenic forming method for a large-size aluminum alloy tailored blank component. A refrigerant is used for cooling an aluminum alloy tailored blank to reach an ultralow temperature interval, the temperature of a weld joint zone is made to be lower than the temperature of a base metal zone, and a mold is used for forming the large-size aluminum alloy integrated curved-surface component. The cryogenic forming method for the large-size aluminum alloy tailored blank component has the following technical advantages that (1) the forming limit is high, differential temperature forming of the aluminum alloy tailored blank at ultralow temperature is adopted, the characteristic that the plasticity and strength of the weld joint zone are higher than those of the base metalzone is used, the problem of cracking caused by the large deformation amount of the weld joint zone is avoided; (2) the structure property is good, the structure property is basically not changed in the forming process at ultralow temperature, the original structure state is recovered after forming, and damage to the internal structure is not generated; and (3) the forming load is low, cryogenic lubricating layers are formed on work faces of the tailored blank and the mold, the friction resistance and forming force of the blank are lowered, the tonnage and manufacturing cost of large equipmentare reduced, and the cryogenic forming method is suitable for various large-size aluminum alloy integrated thin-wall curved-surface components in the aerospace field.

Description

technical field [0001] The invention relates to the technical field of plate forming, in particular to a freezing forming method for large-size aluminum alloy tailored welded blank components. Background technique [0002] Aluminum alloy has excellent specific strength, specific stiffness and corrosion resistance, and has always been one of the main structural materials of aerospace equipment such as rockets and aircraft. Aluminum alloys account for about 80% of the structural mass of launch vehicles, and more than 50% for civil aircraft. With the development of a new generation of large rockets and large aircraft, there is an urgent need for large-scale integral structural aluminum alloy thin-walled components to meet their requirements for high reliability, long life and lightweight. [0003] The existing technical route for the manufacture of aluminum alloy thin-walled components is "formation of plates into blocks + welding into integral components + heat treatment to c...

AI Technical Summary

Problems solved by technology

[0004] However, there are insurmountable problems in the manufacture of large-scale aluminum alloy thin-walled monolithic components using existing cold forming and hot forming technologies

For cold forming technology, when the ordinary deep drawing process is adopted, large-size thin-walled blanks are prone to wrinkling, and FSW welds are prone to cracking defects, so the coexistence of wrinkling and cracking defects cannot be solved; when the most advanced sheet metal hydroforming process is adopted , the forming force of a 5m-diameter component reaches 800MN, and the ultra-large fluid high-pressure forming equipment is expensive and risky

For thermoforming technology, the FSW weld seam softens under heating, resulting in cracking during the forming process that cannot be overcome; moreover, the microstructure and properties of the thermoforming process are difficult to control

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