The corrosion behavior of AZ91 bulk alloy and thin films

Abstract

Purpose The purpose of this study is to campare the corrosion behavior of Az91 films and bulk sample, in the objective to provide reference for the corrosion resistance improvement of Mg alloys. Design/methodology/approach AZ91 films with various thickness values are produced by magnetron sputtering technique, and the corrosion behavior was characterized by immersion tests and electrochemical measurements. Findings The AZ91 films exhibited a preferred orientation with basal planes parallel to the surface and increased densification with the increase of thickness, and a superior corrosion resistance for the AZ91 films compared with the bulk sample. Originality/value The preferred (0002) basal planes in AZ91 films benefited the corrosion resistance and the nanoscale AZ91 films facilitated the development of a dense passivation film. Consequently, AZ91 film exhibited a superior corrosion resistance.