Characterization of Pre-Aged AA6061-T6 Sheet Material for Aerospace Applications

Abstract

In previous papers it was shown for alloy AA6061 that the artificial aging response is adversely affected by natural aging at room temperature. A suitable pre-aging procedure at elevated temperatures immediately after solution heat treatment is effective in reducing the detrimental effects of natural aging on the artificial aging kinetics. The hereby produced temper T4{*} shows an increased aging response and exhibits after artificial aging to temper T6 a much higher level of mechanical properties. In the present work pre-aged AA6061 material is produced on industrial scale and is characterized in comparison to a standard production in terms of static and dynamic material properties in the peak aged temper T6. The effects of the pre-aging on artificial aging kinetics and corrosion performance as well the fatigue crack propagation rate and fracture toughness behaviour is presented in detail and the results are discussed in view of application in the aerospace industry.