Effect of polytetrafluoroethylene content on electrochemical anticorrosion behaviors of electroless deposited Ni-P and Ni-P-polytetrafluoroethylene coatings in seawater

The Ni-P and Ni-P-polytetrafluoroethylene (FTFE) coatings with various PTFE contents were electroless deposited on carbon steel and characterized through X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy. The microstructural morphologies of the coatings significantly varied with the PTFE content. As a result, the electrochemical anticorrosion capabilities were seriously decreased with the increase of the PTFE content. The coating with a trace PTFE (PTFE emulsion concentration of 0.2 mL/L in the plating bath) possessed excellent anticorrosion both in sterilized and unsterilized seawater which has been attributed to the absence of nano pores blocked by the incorporated trace PTFE nano particles. (C) 2011 Elsevier B.V. All rights reserved.