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 siloxane-acrylate 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°. Such coatings can be recommended for application for the parts operating in friction units and fabrication of anti-icing coatings.