Investigation of quench sensitivity and transformation kinetics during isothermal treatment in 6082 aluminum alloy

The quench sensitivity of 6082 aluminum alloy was investigated by time–temperature–property (TTP) curves. The sensitive temperature of quenching ranges from 250 °C to 440 °C in 6082 Al-alloy, and the nose temperature is about 360 °C. During isothermal treatment process, the Mg2Si particles precipitate from the supersaturated solid solution, and the precipitation rate is the highest at the nose temperature. A number of rod-shaped β′ and β particles precipitate in the early stage of isothermal treatment at 360 °C. Prolonging the holding time leads to more and coarser β particles in the matrix. Both the precipitation of β′ and β particles results in loss of solute and decreasing of the subsequent age hardening effect. Also, the important coefficients k2–k5 and critical cooling rate for 6082 Al-alloy are identified, and the properties after different rates of cooling were predicted using quench factor analysis.