Surface Properties Contrast between Al Films and TiO₂ Films Coated on Magnesium Alloys by Magnetron Sputtering

Al films and TiO₂ films were separately coated on AZ31 magnesium alloy substrates by means of magnetron sputtering method. The surface properties of the samples were explored and compared. Scanning electron microscope (SEM) observed the compact structure characteristics of as-deposited Al films and TiO₂ films. After heat treatment under 200ºC for half an hour the films kept the compact structure characteristics and there didn’t exist structural defects on the surface of the films. Nano-indentation measurement results display that the micro-hardness of as-deposited Al film and TiO₂ film reaches about 1.90 Gpa and 1.51 Gpa, separately. Al film is a bit harder than TiO₂ film. Finally, the corrosion experiments in simulated body fluid initially indicate the different corrosion properties for Al film and TiO₂ film. Al film presents more effective anti-corrosion properties than TiO₂ film.

Keywords:
Surface properties; Magnesium alloy; Al films; TiO₂ films; Magnetron sputtering