Hot forming-quenching integrated process with cold-hot dies for 2A12 aluminum alloy sheet

摘要

A novel process called hot forming-quenching integrated process with cold-hot dies was proposed to improve the formability and avoid thermal distortion in solution heat treatment. In this process, the heated lower dies were used to improve the forming temperature and the cooled upper dies were utilized to accomplish quenching and reduce thermal distortion. The effects of temperatures of the hot dies ranging from 100 to 450 °C on strengthening were systematically investigated. The strengths were measured by Vickers hardness test and uniaxial tensile test. It was found that the temperature of heated lower dies could be improved to 450 °C to slow the temperature decrease of heated sheet besides obtaining excellent strength. The temperature of both hot dies could only be improved to 250 °C. The strengthening phase was the dispersed lath-shaped S precipitate with an average cross-section of approximately 50x100 nm.