Study on cryogenic deep drawing of 2219 aluminum alloy spherical shell

Abstract

In order to meet the urgent needs of aluminum alloy integral shell, a new forming process is required to solve the problem of splitting at room temperature. The plasticity of aluminum alloy is significantly improved at cryogenic temperature, and a novel cryogenic forming method was developed recently. In this paper, a cryogenic forming unit was established to study the cryogenic drawing behavior. The effects of sheet diameter on the wrinkling and deformation behaviors were analyzed by experiments and numerical simulations. The study showed that a spherical shell with a diameter of 200mm and a thickness-diameter-ratio of 1.0% could be formed at -160°C, which split at room temperature. The drawing depth was increased 74.3% at cryogenic temperature. The tendencies of wrinkling and splitting were controlled by the appropriate sheet diameter. It is concluded that cryogenic deep drawing has great potential for forming aluminum alloy integral shells.