Quantitative analysis of precipitation in an Al-Zn-Mg-Cu-Li alloy

The precipitate size distribution and morphology in an Al-Zn-Mg-Cu-Li alloy have been studied by small angle X-ray scattering (SAXS). The results show that the precipitates belong to flat ellipsoids of revolution and their axis ratio range is between 0.2 and 0.4 aged at different conditions. To verify the validity, the results of SAXS have been compared with that of TEM. This study has also constructed the logarithm Gaussian distribution of effective size and the Maxwell distribution of particles mass with gyration radius by means of a prior assumed model of the size distribution. The geometric mean and distribution width for both type distribution curves increase with kinetic strength Ks, which indicates the characteristics of the size distribution in space during aging.