Abstract:Temperature variation and solution treatment of high strength aluminum alloy were investigated with temperature data acquisition system, microstructural observation, mechanical properties test, electrical conductivity measurement and differential scanning calorimetry (DSC) analysis. Specimens with two dimensions were employed in the experiment. The results indicate that the specimens with large size undergo low solution temperature and short time, giving rise to the reduction of hardening precipitates. The optimized solution treatments for specimens with dimensions of 25 mm×25 mm×2.5 mm and 70 mm×60 mm×20 mm are (480 °C, 30 min) and (480 °C, 90 min), respectively. The densities of GP zones and η′ phases of the small specimen are higher than those of the large specimen, which is consistent with the properties of the alloys.

Key words: aluminum alloy; specimen size; solution treatment; heating rate; hardening precipitate