The effects of pre-aging treatments on paint bake response of an Al-Mg-Si sheet alloy

摘要

The age-hardening Al-Mg-Si alloys are well established for automotive body sheets. In Europe, the AA6016 alloy is the preferred alloy for external application. This alloy suffers from low aging kinetics and therefore shows only a slight artificial aging response during paint baking, referred to as the paint bake response. The application of a multi-stage pre-aging treatment causes a marked increase in the precipitation kinetics of AA6016. It is proposed that pre-aging results in a stabilized structure containing finely distributed precipitation nuclei, which entails a higher paint bake response and a reduced natural aging rate compared to conventional material.