Properties of aluminum oxide thin film obtained by metal plasma immersion ion implantation and deposition after zirconium-based pretreatment

Abstract

Aluminum oxide thin films were obtained by metal plasma immersion ion implantation and deposition (MePIIID) and subsequently converted by a zirconium based surface pretreatment. Thin films atomic composition was studied using Rutherford backscattering spectrometry (RBS) and forward recoil spectrometry (FRS), especially for hydrogen measurement. Film morphology and thickness were investigated by atomic force microscopy (AFM) and field emission scanning electron microscopy (FE-SEM). Wettability was assessed by contact angle measurements. The corrosion behavior was investigated using EIS measurements and potentiodynamic polarization curves. Results pointed out to the deposition of a highly oxidized film with high hydrogen content with smooth surface. After conversion, wettability was greatly enhanced as denoted by the 50% decrease of the contact angle after conversion. The conversion treatment decreased the values of icorr from 1.51 to 0.75 μA cm−2. Excellent corrosion resistance was achieved when an acrylic coating was applied over the converted MePIIID layer, further decreasing icorr to 0.004 μA cm−2.