Influence of Short-Term Heat Treatment on the Mechanical Properties of Al–Mg–Si Profiles

Abstract

Aluminum profiles—for instance, profiles made of precipitation-hardenable alloys—are increasingly used for decorative details in the automotive industry. Typically, after hot extrusion and at least two to three days of natural aging (NA), the aluminum profiles are artificially aged. A commercial EN AW-6060 alloy of high purity was used for this investigation. Tensile tests were used as the main measurement method. This article focuses on the effect of short-term heat treatment on the point in time at which a significant increase of the ultimate tensile strength (UTS) during NA can be measured. Short-term heat treatment is shown to delay this point in time by almost four days, but it increases the variation of UTS. A heterogeneous temperature profile during short-term heat treatment was identified as one reason for this result. Finally, a strategy for minimizing variations in mechanical properties of artificially-aged aluminum alloys was developed, based on the experimental results of this study.

Keywords

• aluminum
• artificial aging
• mean variation
• natural aging
• ultimate tensile strength