Construction And Characterization Of Marine Anticorrosion And Antifouling Coatings By Cold Spray Deposition

Corrosion and biofouling are two key problems for marine infrastructures during their long term services.Various strategies in particular coating technologies have been developed to protect steel structures from corrosion and fouling.Cold spray?CS?is a novel and promising method to deposit powder at low temperature,which is of great prospect for preparing temperature sensitive coatings,such as diamond/Cu composite coatings and organic/inorganic nanocomposite coatings.However,there are so far few reports elucidating the deposition of anticorrosion and antifouling coatings by CS for marine applications.Main contents and conclusion of this study are listed as follows:1.Cold sprayed diamond-Cu composite coatings and their propertiesSliding parts in marine environment always face a synergistic effect of wear,corrosion and fouling instead of only one of them.Herein,diamond-Cu composite coatings were successfully deposited on stainless steels by cold spraying employing diamond powder coated with a thin copper?Cu?layer which was acquired using electroless plating process.Results showed that a carbon content as high as 31.7%was realized in the diamond-Cu composite coatings,and diamond particles were well embedded in the coating.The constructed composite coating showed markedly improved wear resistance performance assessed by pin-on-disk testing carried out in artificial sea water,in turn enhancing its tribocorrosion property.The diamond-Cu composites coatings also show a good inhibitive effect on the diatoms adhesion.This study presents a promising approach to fabricate protective coatings for marine infrastructures for tribocorrosion resistance/antifouling applications.2.Vacuum cold sprayed superhydrophobic TiO₂ nanocoatings and their propertiesSuperhydrophobic surfaces have drawn great interests due to their potential applications such as anti-corrosion,anti-fouling,etc.A superhydrophobic TiO₂-oleic acid?OA?nanocomposite coating was fabricated by a novel vacuum cold spray?VCS?process at room temperature.The OA functionalized nano-TiO₂ powders were synthesized through sol-gel methods.Results showed that the content of OA immobilized on TiO₂ nanoparticles could influence the deposition effect during the VCS process,in turn controlling the wettability of nanocoatings acquired.The wettability of the nanocoatings could be adjusted by altering the content of OA in the starting nanocomposite powder.The maximum static water contact angle and the minimum sliding angle were obtained at 151.2°and 1.2°,respectively,with the molar ratio of OA to TiO₂ at 1:10.Additionally,it was observed that the newly constructed superhydrophobic coatings display mechanical durability.This study provides a novel method for fabricating inorganic-organic nanocomposite superhydrophobic coatings for long-term functional applications.