Carbon-free SiOx ultrathin film using atmospheric pressure plasma jet for enhancing the corrosion resistance of magnesium alloys. (December 2017)

• Record Type: Journal Article
• Authors: Kuo, Yu-Lin; Chang, Kuang-Hui; Chiu, Chun
• Is Part Of: Vacuum. Volume 146(2017)
• Page Start: 8
• Page End: 10
• Publication Date: 2017-12
• Subjects: Atmospheric pressure plasma jet (APPJ) -- Magnesium alloy -- Tetraethylorthosilicate (TEOS) -- Corrosion; Vacuum -- Periodicals; 621.55
• DOI: 10.1016/j.vacuum.2017.09.028
• Languages: English
• ISSNs: 0042-207X

Abstract

Abstract: This study describes the use of tetraethylorthosilicate (TEOS) as the precursor to deposit carbon-free silica (SiO2 ) dense film as the anti-corrosion layer on the surface of AZ91D magnesium alloys using an air atmospheric pressure plasma jet (APPJ). From the contact angle measurements, APPJ-deposited silica film on AZ91D represents a more hydrophobic property with a lower total surface free energy of 31.3 mN/m. XPS depth profile analyses revealed the chemical compositions (O and Si) were uniformly distributed through the bulk of the deposited films with a thickness of 207 nm, which also comprises of carbon-free SiO2 ultrathin films. The electrochemical impedance spectroscopy (EIS) measurements and corrosion morphologies of 14-day immersion test of deposited films and AZ91D samples in 3.5 wt % NaCl solution are also investigated. The results indicate ultrathin silica coating not only alter the surface property, but also improve the corrosion resistance of AZ91D magnesium alloys. Highlights: We investigated the deposition of SiOX film as functional layer by atmospheric pressure plasma jet. Ultrathin, carbon-free and stoichiometric SiO2 film was obtained. The corrosion resistance of magnesium alloys was enhanced through APPJ-deposited SiOx film.