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 degrees C to 440 degrees C in 6082 Al-alloy, and the nose temperature is about 360 degrees C. During isothermal treatment process, the Mg(2)Si particles precipitate from the supersaturated solid solution, and the precipitation rate is the highest at the nose temperature. A number of rod-shaped beta' and beta particles precipitate in the early stage of isothermal treatment at 360 degrees C. Prolonging the holding time leads to more and coarser beta particles in the matrix. Both the precipitation of beta' and beta 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. (C) 2011 Elsevier Ltd. All rights reserved.