TTP Curves and Microstructural Evolution Mechanism After Quenching in Aluminum Alloy 6082

Abstract

Temperature-time-property (TTP) curves for aluminum alloy 6082 were acquired by an interrupted quenching method. The TTP curves presented a ''C''-shape and the critical temperature range was 240-440°C with temperature at the nose of the C-curve of approximately 335°C. At this temperature, the greatest rate of second phase development and the largest, and most rapid, drop in hardness was observed. The change was approximately 50% of the maximum when isothermally held or 50 s. Microstructural evolution of the quenched aluminum alloy 6082 was analyzed with a transmission electron microscope (TEM). TEM analysis results showed that secondary phase particle growth rate was controlled by diffusion. Growth was rapid during the critical temperature range. When the holding time was prolonged, the spherical and needle-shaped precipitates, which provided a significant strengthening effect, rapidly transformed into coarse, rodshaped precipitates. This over-aged condition resulted in loss of the precipitate strengthening effect.

Development of a novel forming tool for the production of high-strength aluminum components with tailored properties

“…By this, the production of components with locally adapted mechanical properties is possible. Investigations by Gao et al revealed, that the alloy AA6082 has a critical cooling range between 240 °C and 440 °C [8]. Studies by Sajadifar et al demonstrated that various cooling rates can be obtained by adjusting the tool temperature [9].…”

Microstructure and Mechanical Properties of the Joints from Coarse- and Ultrafine-Grained Al-Mg-Si Alloy Obtained via Friction Stir Welding

“…Depending on the region in the SZ, they underwent dissolution (Figure 5c); however, in some, coarser precipitates were observed (Figure 5d). Based on the literature analysis, they can be assumed to be β' (rods) and β (plates) [34,35], which contributed to the strengthening being lower in comparison to the β″ precipitates. Between the welds, two main differences were observed.…”

Effects of germanium on quench sensitivity in Al–Zn–Mg–Zr alloy

“…From these results, it was evident that the stability of supersaturated solid solution in Ge-bearing was enhanced as compared to the based alloy. It was pointed out that the incubation period represented the stability of the supersaturated solid solution [16], i.e. higher stability of the solid solution equaled to a longer incubation period.…”