The effects of Cu addition on the microstructure and thermal stability of an Al–Mg–Si alloy

The effects of Cu addition on the microstructure and thermal stability of 6082 Al–Mg–Si alloys were investigated. The results show the Q′ precipitates are formed when aged at 170 °C for 4 h in 6082 alloy with 0.6% Cu addition. The hardness value of the alloy with 0.6% Cu is always distinctly higher than that of the alloy without Cu during isothermal treatment at 250 °C. Based on the TEM and three-dimensional atom probe (3DAP) results, the thermal stability of the 6082 alloys with Cu addition is discussed with respect to the distribution of Cu.