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

摘要

The quench sensitivity of 6082 aluminum alloy was investigated by time-temperature-property (TTP) curves. The sensitive temperature of quenching ranges from 250 ℃ to 440 ℃ in 6082 Al-alloy, and the nose temperature is about 360 ℃. During isothermal treatment process, the Mg_2Si particles precipitate from the supersaturated solid solution, and the precipitation rate is the highest at the nose temperature. A number of rod-shaped p' and p particles precipitate in the early stage of isothermal treatment at 360 ℃. Prolonging the holding time leads to more and coarser p particles in the matrix. Both the precipitation of P' and p particles results in loss of solute and decreasing of the subsequent age hardening effect. Also, the important coefficients k_2-k_5 and critical cooling rate for 6082 Al-alloy are identified, and the properties after different rates of cooling were predicted using quench factor analysis.