In Situ Real-Time Monitoring of Aging Processes in an Aluminum Alloy by High-Precision Dilatometry

A detailed understanding of the atomistic processes governing the age hardening response of light metal alloys is of vital importance for the optimization of their properties. While a static characterization of metastable precipitates is possible, e.g., by advanced microscopic techniques, the kinetic aspects of the underlying formation of phases are by far more difficult to assess. In this work we present isothermal, high-stability laser dilatometric measurements, during the natural and artificial aging of a commercial aluminum alloy (Al-Mg-Si), with a rate resolution below 1 nm/h. The results of this case study show that the presented dilatometric technique allows for direct monitoring of the precipitation process with an unprecedented accuracy on the volume as well as on the time scale.