Modeling of GP (I) zone formation during quench in an industrial AA7449 75mm thick plate

The GP(I) zone formation during quench is simulated in an industrial Aluminumalloy AA7449 75mmthick plate by using a multi-class precipitation model. For this purpose, results of in situ SAXS experiments are reported. A methodology is presented that takes advantage of the collected data to derive i - a thermodynamic description for GP(I) zones from reversion heat treatments by using a solubility product and ii - the influence of excess vacancies on diffusion coefficients. This approach allows reproducing reasonably well the GP(I) zone formation measured during rapid cooling. Further, the simulated as-quenched surface yield strength compares well with experimental results reported in the literature.