Preliminary Study of DLC Coatings Aiming to the Corrosion Protection of Ferrous Materials

Abstract

Zinc hot-dip galvanizing is one of the most effective methods for the corrosion protection of ferrous substrates. However, the failure of zinc coatings is possible when exposed to harsh environments for rather long periods. The application of a thin diamond like carbon (DLC) film on the top of the zinc coating might be a promising method for promoting their corrosion resistance. In the present work, a DLC thin film was deposited on zinc galvanized coatings by Plasma Enhanced Chemical Vapor Deposition. The as-formed film was composed of nanostructured and amorphous areas. The electron diffraction patterns acquired from the nanograins correspond to carbon phases with d-spacing ranging from diamond to graphite. Additionally, after 18 days of exposure in a simulated marine atmosphere, the DLC coated samples were proven to be more resistant than the naked galvanized coatings indicating its potential to improve the corrosion resistance of galvanized ferrous materials.