Abstract:The forming behaviour of AW-7075-T6 sheet was studied across a range of shock heat treatment (SHT) temperatures of 200-480 °C. After SHT, formability of the samples was investigated by tension and deep drawing tests at room temperature. Differential scanning calorimetry (DSC) was used to study the precipitation states of the AW-7075 sheet in the as-received and shock heat treated conditions. Formability was started to improve with increasing shock heat treatment temperature from 300 °C onwards. Strain hardening resulted from the dissolution of η′ precipitates and the coarsening of remaining precipitates were found to contribute to the increase in formability at room temperature. Re-precipitation and coarsening of the precipitates were responsible for the post-paint baking strength of SHT samples.

Key words: shock heat treatment forming; AW-7075-T6 sheet; formability; precipitation kinetics