An experimental analysis of three different corrosion behaviors, passivation, pitting and uniform, of electrodeposited Chromium-Nano diamond composite coating on porous materials

Abstract

Incorporation of nano scale particles in coatings of metals are known as nano composite coatings are a new form of materials with enhanced hardness, wear, and corrosion resistances. In this study, pre-alloy metal powder metallurgy specimens were subjected to electrolytic coating of pure chromium and Cr-ND (Chromium-nano diamond). The influences of the co-deposited ND particles on passivation, pitting and uniform corrosion behavior of the chromium coatings were experimentally inspected and compared with pure chromium coating and non-coated specimens. The corrosion behaviors of the samples were analyzed by Polarization Resistance, Cyclic Voltammetry and Electrochemical Impedance Spectroscopy measurement methods under 3.5 %wt. NaCl solution. Furthermore, characterization tests were carried out using an optical microscope, SEM (Scanning Electron Microscope), EDS (Energy Dispersive X-Ray Spectroscopy), XRD (X-Ray Diffraction) and AFM (Atomic Force Microscope). According to the obtained results, it was observed that as compared to pure chromium coatings and non-coated specimens, a convincing improvement in the corrosion behavior of the Cr-ND coatings was obtained because of the incorporation of the ND particles in the chromium matrix.