An industrial PECVD application: modified SiO_2:films deposited on OT59 brass as wear and corrosion protection

摘要

PECVD technique was used to deposit on OT59 brass surface Si0_2 coatings. The aim was to obtain a surface treatment that improve the quality perfomance of industrial objects whose life-time had to be at least 5-10 years corrosion resistant. The deposition was performed in RF (13.56 MH) plasma with Hexamethyldisiloxan (HMDSO) and O_2 mixture at various temperatures without any solvents and without particular surface pretreatments. Different thickness of SiO_2 film was obtained varying time of plasma exposure. Surface electrochemical and chemical characterisation of deposited films were performed by means of different techniques [DC (Tafel curves) and AC (Electrochemical Impedance Spectroscopy - EIS) Electrochemical techniques, SIMS (Secondary Ion Mass Spectrometry), XPS (X-Ray Photoelectron Microscopy), SEM (Scanning Electron Microscopy), and other technical tests]. The excellent protection from wear, corrosion and oxidation was evident after the examination of some industrial finished PECVD treated objects. The resulting coatings were resistant to acid, organic solvent and basic solutions and maintained their capability of remaining flexible.