Influence of ion energy on morphology and corrosion properties of Mg alloys formed by energetic PVD processes

Different PVD processes - magnetron sputtering, ion beam sputtering and vacuum arc deposition - are used to produce novel corrosion resistant Mg alloys with the average energy per deposited atom increasing from 5-10 to 15-45 eV. Correspondingly, a transition from a 3-dimensional columnar growth regime towards a layer-by-layer growth at increased energies was observed with the film texture changing from a weak basal texture towards a highly oriented film with the c-axis normal to the surface. Additionally, a higher energy helped stabilizing supersaturation, especially for Mg-Ti alloys. However, only a weak influence of the morphology on the corrosion rates was observed, which were mainly governed by the chemical composition of the films.