Synergistic effect of water solubility sulfhydryl compound and rare-earth ions on the microstructure, composition, and corrosion resistance of brass.

[Display omitted] • Organic-inorganic hybrid film based on TGA and Y(III) were fabricated on brass. • TGA-Y(III) hybrid film is composed of a double-layer structure. • Well-ordered Y 2 O 3 grains formed by cathodic deposition prevented the pitting. • The adsorption mode of TGA on Cu(1 0 0) surface was parallel. • The presence of zinc in brass improved the deposition level of Y 2 O 3. The aim of the present research is to develop one new strategy to modify the brass surface with well anticorrosion performance. Here, utilizing the synergistic effect between thioglycolic acid (TGA) and Y(III), one organic–inorganic hybrid film composed of a self-assembled film at the top and an oxide film at the bottom was fabricated on brass surface. The formation process of the hybrid film contained the parallel adsorption of TGA molecules, surface oxidation of copper accompanied by zinc dissolution, interface deposition of Y 2 O 3 and assembly of Cu-TGA chelates. Electrochemical results indicated that the protection efficiency was 99.2% under the optimum conditions and the value remained at 92.1% after 12 h immersion in 3.5 wt% NaCl solution. Due to the good water solubility of the film-forming substance and excellent anticorrosion performance of the fabricated film, this strategy has important application potential in the field of surface functionalization of copper alloys. [ABSTRACT FROM AUTHOR]