The influence of heat treatment of inorganic conversion coatings produced by sol-gel dip coating on the anticorrosive properties of alumina films deposited on steel substrate – Part I: Single conversion coatings

• Published in: Surface & coatings technology Vol. 372; pp. 190 - 200
• Main Authors: Braga, Antonio Vitor de Castro, do Lago, Dalva Cristina Baptista, Pimenta, André Rocha, de Senna, Lilian Ferreira
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 25.08.2019; Elsevier BV
• Subjects: Alumina; Aluminum oxide; Boehmite; Carbon steels; Conversion coating; Conversion coatings; Corrosion prevention; Dip coating; Dip coatings; Electrochemical impedance spectroscopy; Heat treating; Heat treatment; Immersion coating; Morphology; Protective coatings; Silicon dioxide; Sol-gel; Sol-gel processes; Substrates; Heat treatment; Dip coating; Alumina; Sol-gel; Conversion coating
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2019.05.040

Boehmite and silica conversion coatings were produced by sol-gel dip coating and heat-treated at different temperatures to improve the anticorrosive performance of alumina film deposited on AISI 1020 carbon steel substrate. SEM and XRD were used to evaluate, respectively, the morphology and composition of the conversion coatings. After covering these conversion coatings with alumina film, the systems were characterized by electrochemical impedance spectroscopy. Although both silica and boehmite improved the anticorrosive performance of the alumina film when applied as a conversion coating, the heat treatment temperature used in each case played a decisive role in their properties. •Alumina film was deposited via sol-gel dip coating on inorganic conversion coatings.•Boehmite and silica conversion coatings were heat treated under different temperatures.•The heat treatment influenced on the properties of the conversion coatings.•Anticorrosive properties of the systems are improved by the conversion coatings.