Enhanced aging kinetics in Al-Mg-Si alloys by up-quenching

Precipitation-hardened aluminium alloys typically obtain their strength by forming second-phase particles, which, however, often have a negative effect on formability. To enable both lightweight construction and forming of complex parts such as body panels, high strength and formability are required simultaneously. Cluster hardening is a promising approach to achieve this. Here, we show that short thermal spikes, denoted as up-quenching, increase aging kinetics, which we attribute to the repeated process of vacancies being formed at high temperatures and retained when cooled to lower temperatures. Combined with further heat treatment, the up-quenching process promotes rapid and extensive cluster formation in Al-Mg-Si alloys, which in turn generates significant strengthening at industrially relevant heat treatment time scales. The high elongation values also observed are attributed to reduced solute depleted zones along grain boundaries. Thermal treatments are important for controlling the microstructure and mechanical properties of precipitation-hardened alloys. Here, an up-quenching process enhances clustering kinetics in an Al-Mg-Si alloy, attributed to retained high temperature vacancies assisting diffusion at low temperature.

Automated summary

Research indicates that up-quenching process can promote cluster formation in Al-Mg-Si alloys, enhancing the strength and elongation of the material. This method helps achieve lightweight construction and forming of complex components in aluminum alloys.