Enhancing the anti-tarnish and mechanical properties of gold-coated silver sheets for decorative applications using TiO2 film protection

Abstract

This study explores an innovative method to enhance the anti-tarnish and mechanical properties of gold-coated silver sheets, targeting decorative applications through the TiO2 film coatings. The research focuses on gold films with a thickness of approximately 100 nm, and TiO2 films ranging from 10 to 31 nm. It was observed that the color of the multilayer coatings exhibited significant sensitivity to variations in thickness, indicating that a TiO2 coating with a thickness around 20 nm could be optimally applied to the gold film, maintaining an acceptable ΔE value. X-ray photoelectron spectroscopy analysis demonstrated the TiO2 film’s potential to inhibit the formation of Ag2S on the surface, thereby enhancing tarnish resistance. Furthermore, the application of a 20 nm TiO2 layer reduced the friction coefficient from 0.28 to 0.24 for gold-coated silver. Durability tests involving 1,000 abrasion cycles revealed that the gold film without TiO2 protection experienced delamination, with only about 57 % of the coated area remaining intact. In contrast, the samples protected with a TiO2 layer retained approximately 90 % of the coating, underscoring the effectiveness of TiO2 in preserving the structural integrity and appearance of the gold-coated silver sheets.