Effect of aging parameters on the mechanical properties of naturally aged Al-Mg-Si alloy

Among the extruded products within the Al-Mg-Si system, AA6082 alloy is regarded as high strength alloy which is used for automotive structural applications. Room temperature storage in between the solution heat treatment and the paint bake cycle is unavoidable problem and undergoes natural aging. Hence, natural aging time in the conventional T4 condition must be modified after the solution heat treatment in order to avoid any hardening during storage before forming processes. The present work was investigated to improve paint bake response of extruded 6082 profiles by employing pre-aging in between the solution heat treatment and the paint bake in order to obtain sufficient strength for the required in-service dent resistance. Pre-aging treatment was performed for 5 min at 180 degrees C, 200 degrees C and 225 degrees C to improve bake hardening response of extruded 6082 profiles. Tensile tests and micro hardness measurements are performed to determine the natural aging effect on mechanical properties. In order to understand the precipitation hardening of this aluminum profile with a different natural aging time, differential scanning calorimetry measurements are performed.