Surface science methods including scanning Auger microscopy (SAM), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy have been used to study the initial growth of chromate conversion coatings on aluminum 2024-T3 alloy, using a coating bath formed by dissolving CrO3, Na2Cr2O7 and NaF in water. The objective is to learn more about growth mechanism on the different microstructural regions of this alloy surface, including the second-phase particles and the alloy matrix.