Ultra-low temperature medium pressure forming method for complex curved-shaped components

Abstract

Disclosed is an ultra-low temperature medium pressure forming method for complex curved-shaped components. The method includes steps of distributing a blank by die closing preforming and forming the complex curved-shaped components by ultra-low temperature medium pressurization, comprising: placing a plate on a female die and tightly pressing the plate by a blank holder; driving a male die to move downwards to make the plate distribute the blank in advance in a large-area mode, thus forming a prefabricated plate blank; filling a cavity with an ultra-low temperature medium to make the prefabricated plate blank be gradually attached to a molded surface of a female die cavity under the pressure action of the ultra-low temperature medium, and thereby forming the complex curved-shaped component; and removing the male die blank holder and taking out the formed complex curved-shaped component.

What is claimed is: 
     
         1 . An ultra-low temperature medium pressure forming method for complex curved-shaped components, comprising distributing a blank by die closing preforming and forming the complex curved-shaped components by ultra-low temperature medium pressurization, wherein comprises steps as follows:
 S 1 , placing a plate on a female die, and applying a blank holding force to a blank holder to make the blank holder press the plate tightly;   S 2 , driving a male die to move downwards to make the plate distribute the blank in advance in a large-area mode under the action of the female die and the male die, forming a prefabricated plate blank, wherein the female die and the male die are mismatched in molded surfaces; adjusting the blank holding force on the blank holder according to a deep-drawing depth of the plate to guarantee that a cavity between the prefabricated plate blank and the male die is kept in a sealed state;   wherein a sealing element is arranged at a contact position of an upper surface of the blank holder and the male die, the blank holder applies a unit blank holding force of less than 5 MPa in step S 1 , and the blank holder applies a unit blank holding force of more than 7 MPa after being adjusted in step S 2 ;   S 3 , filling the cavity between the prefabricated plate blank and the male die with an ultra-low temperature medium through a booster pump and a circulation pipeline, and enabling the prefabricated plate blank to be gradually attached to the molded surface of the female die under the pressure action of the ultra-low temperature medium, forming the complex curved-shaped component; and   S 4 , recycling the ultra-low temperature medium in the cavity, driving the male die to move upwards, removing the blank holder, and taking out the formed complex curved-shaped component.   
     
     
         2 . The ultra-low temperature medium pressure forming method for complex curved-shaped components according to  claim 1 , wherein the male die is a cambered die in smooth transition, and a molded surface with complex shape is arranged in the female die. 
     
     
         3 . The ultra-low temperature medium pressure forming method for complex curved-shaped components according to  claim 1 , wherein, before step S 1 , the male die is cooled to a set temperature of lower than −160° C. 
     
     
         4 . The ultra-low temperature medium pressure forming method for complex curved-shaped components according to  claim 1 , wherein a solution cavity for accommodating the ultra-low temperature medium is arranged in the male die, and the solution cavity is communicated with a low-temperature vessel and the booster pump through a circulation path, wherein the low-temperature vessel is used for placing the ultra-low temperature medium. 
     
     
         5 . The ultra-low temperature medium pressure forming method for complex curved-shaped components according to  claim 4 , wherein pressurization pressure of the booster pump is no more than 100 MPa. 
     
     
         6 . The ultra-low temperature medium pressure forming method for complex curved-shaped components according to  claim 1 , wherein the ultra-low temperature medium is liquid nitrogen, liquid argon, or liquid helium. 
     
     
         7 . The ultra-low temperature medium pressure forming method for complex curved-shaped components according to  claim 1 , wherein the plate is a rolled aluminum alloy plate having a wall thickness of 0.1-10 mm, and the plate is Al—Li alloy, Al—Cu alloy, Al—Mg—Si alloy, or Al—Zn alloy.