Corrosion behaviors of sputter-deposited steel thin film for electrical resistance sensor material

This paper describes an experimental approach for the study of electrochemical characteristics of the steel thin film with a thickness of 600 nm as an electrical resistance sensor material with an improved sensitivity for the corrosion rate measurement. The thin film was deposited onto the glass by magnetron-sputtering using carbon steel targets in an Ar atmosphere. The physical properties of fabricated thin films were investigated by the X-ray diffraction (XRD) analysis, adhesion test and Auger electron spectroscopy (AES). To ensure that the thin film could replicate the corrosion behavior of a bulk steel, the electrochemical polarization tests were performed. It was revealed that the adhesion strength and the electrochemical behaviors of thin films were comparable to those of the bulk steel by controlling the oxygen level in the films during the deposition process. A sensitive thin film electrical resistance (TFER) sensor could be fabricated with this film and the enhanced sensitivity enables quick measurement of the corrosion rate. The TFER sensor with the multiple-line pattern showed the enhanced sensitivity to localized corrosion phenomena. It was demonstrated that this method could be a reliable tool for corrosion monitoring.