T7 HEAT TREATMENT
T7 heat treatment consists of solution heat treatment and extreme aging steps. Sudden cooling of the material by keeping the material at 520 °C or above for a certain period of time in order to take the alloy elements within the aluminum alloy into solid solution. In some aluminum alloys (for example 6060/6063/AlMgSi0.5), the sudden cooling of the material with air or water after a hot process such as extrusion results in solution heat treatment.
The aging process step, which is the last step of the T7 heat treatment, allows the aluminum alloy to be kept at room temperature, and the alloy elements in the solid solution are separated from the solid solution and precipitated, increasing the hardness of the material by the “precipitation hardening” mechanism.