Method for forming aluminum alloy thin-walled curved part by ultra-low temperature gradient drawing

A method for forming an aluminum alloy thin-walled curved part by ultra-low temperature gradient drawing, comprising forming a deep-cavity thin-walled curved part from an aluminum alloy sheet by controlling formability and flow stress based on an ultra-low temperature gradient, and specifically comprising the following steps:

• step 1:
• placing the aluminum alloy sheet on a die, and closing a blank holder to hold the aluminum alloy sheet in a flange zone;
• step 2:
• filling a cavity of a die shoe with an ultra-low temperature medium to cool a die cavity zone of the aluminum alloy sheet to a set low temperature, and forming an ultra-low temperature gradient in which the temperature of the die cavity zone is lower than the temperature in the flange zone;
• step 3:
• applying a set blank holder force to the blank holder, and controlling a punch to move downwards to form a deep-cavity thin-walled curved part;
• and
• step 4:
• controlling the punch to move upwards, opening the blank holder, and taking out the formed deep-cavity thin-walled curved part.