Polytetrafluoroethylene-oxide coatings on aluminum alloys

Introduction of polytetrafluoroethylene (PTFE) in the oxide layers can significantly improve their practically important properties such as hydrophobic, anti-friction, and anticorrosion. The present work was devoted to the investigation of regularities of plasma electrolytic formation of PTFE-oxide coatings on aluminum in aqueous silicate alkaline electrolyte containing dispersed particles of polytetrafluoroethylene stabilized by siloxanea-crylate emulsion and the examination of their composition, structure, and properties. The coatings obtained have a structure, which is not a conventional one for PEO layers. The surface of the coating consists mainly of the products of decomposition of PTFE and siloxane-acrylate copolymer and additionally contains polytetrafluoroethylene particles. The conditions of fabricating wear-resistant and hydrophobic PTFE-oxide coatings have been established. The water contact angle of the coatings is larger than 90 degrees. Such coatings can be recommended for application for the parts operating in friction units and fabrication of anti-icing coatings. (C) 2016 Elsevier B.V. All rights reserved.