Effect of Solution Treatment Temperature on Microstructure and Properties of 6082 Aluminum Alloy for Automobile Engine

Solution treatment at termperatures of 480-580 ℃ and artificial ageing were performed for 6082 aluminum alloy profiles. The effects of solution treatment temperature on microstructure and properties of the aluminium alloy were studied by optical microscopy, scanning electron microscopy, transmission electron microscopy and tensile testing. The results show that the tensile properties of the aluminum alloy exhibited a trend of increasing first and then decreasing with the increase of solution treatment temperature. The aluminium alloy had the best tensile properties at solution treatment temperature of 540 ℃. And the corrosion resistance of aluminium alloy was gradually enhanced with the increase of solution treatment temperature. When the solution treatment temperature was in the range of 480-580 ℃, the structure of the aluminium alloy was remarkably refined, and a large number of secondary phases were precipitated. When the solution treatment temperature was above 540 ℃, the aluminium alloy was recrystallized and the grains were coarsened. After aging, precipitates free zone (PFZ) in the structure of the aluminium alloy became narrow and even disappeared, which improved the corrosion resistance of the aluminium alloy.