The influence of non-isothermal aging treatment on phase-precipitation behavior and mechanical properties of 6082 aluminum alloy

In this study, non-isothermal aging (NIA) treatment was applied to as-extruded 6082 aluminum alloy to systematically investigate its effects on the alloy's microstructural evolution and mechanical properties. For comparative analysis, the alloy was also subjected to conventional single-stage aging (SA) and dual-stage aging (DA) treatments. In NIA treatment, the solid-solution treated alloys were heated to the top temperature (160 → 190 °C) at different heating rates (10 → 20 K/h), followed by cooling to 140 °C. The results show that the NIA-treated alloy is characterized by a yield strength (YS) of 407.8 MPa, a tensile strength of 414.9 MPa and an elongation of 14.0%, showing a 10.4% increase in YS in comparison to T6-treated one (369.4 MPa). The improved strength is attributed to the finer and longer β" precipitates, which exhibit a uniform distribution within the matrix. Microstructural characterization confirms that the NIA process facilitates continuous nucleation of β" precipitates while inhibiting their coarsening, thereby contributing to the significant strength improvement.