The Influence of Quench Interruption and Direct Artificial Aging on the Hardening Response in AA6082 during Hot Deformation and In-Die Quenching

Abstract

The automotive industry is searching for lightweight solutions to meet emission regulations. Development of an integrated hot forming and in-die quenching process will leverage use of age-hardenable aluminum alloys with high specific strength for applications in volume car manufacturing. Quench interruption and direct artificial aging may reduce the cycle time in a die-quenching process. However, this alters the temperature exposure of the part and results in an altered precipitation and clustering sequence during hardening. To investigate the effect of modified precipitation and clustering on mechanical properties, the process has been simulated by application of a water-cooled compression tool to control the combination of a temperature drop and simultaneous deformation prior to aging. Extruded 4.6 mm thick AA6082 profiles were deformed during different quenching rates and directly transferred to subsequent artificial aging from various temperatures between room temperature and 200 °C. The results indicate insignificant changes of strength and elongation after direct aging from 200 °C compared to specimens cooled to room temperature before aging.