Effects of thermal treatment on hardness of AA6082-T6

This study expounds the effect of thermal treatment on mechanical properties of AA6082-T6 alloy. This aluminum alloy is frequently exploited in welding structures, which causes a mechanical properties deterioration in the Heat Affected Zone (HAZ). Consequently, a thermal treatment is needed to restore most of the lost characteristics but, at the same time, the Unaffected Base Metal (UBM) undergoes a loss. The aim of this work is to provide a model able to predict the response of Brinell Hardness in the UBM zone after postweld thermal treatments. The central composite rotatable design (CCRD) was used to design an experimental plan developing mathematical models as a function of annealing time, and temperature. Statistical approaches have shown a validity of these mathematical models by confirming a good adequacy. These models have been used to construct response surface graphs to describe the effects of the process variables on the mechanical properties of UBM. Finally, an optimization has been performed to show the capability of the used approach.