Nanoindentation hardness, Young’s modulus, and creep behavior of organic–inorganic silica-based sol-gel thin films on copper

In this study, the mechanical properties and creep behavior of hybrid sol-gel silica-based coatings on copper substrates were investigated. Sol-gel processing was used to synthesize the organically modified silanes using mixtures of tetraethoxysilane and vinyltrimethoxysilane or glycidoxypropyltrimethoxysilane precursors. The mechanical and creep properties of the coatings were assessed using nanoindentation. The link between film structure and creep behavior from nanoindentation experiments was examined, and simple mechanical models were used to extract Young’s modulus and viscosity from fits to creep data. It is shown that the creep response of the coatings was influenced dramatically by the chain length and amount of organic substituent.