Investigation of Passivation, Pitting and Uniform Corrosion Performances of Chromium Coatings Reinforced with Nano Diamond Particles on Porous Powder Metallurgy Specimens

摘要

In this study, electrolytic coating of pure chromium and Cr-ND (nano diamond) were applied on pre-alloy metal powder metallurgy specimens. The effects of the co-deposited ND particles and coating duration on the passivation, pitting and uniform corrosion behaviors of the chromium coatings were comparatively investigated with pure Cr coating and non-coated samples. Polarization Resistance, Cyclic Voltammetry and Electrochemical Impedance Spectroscopy measurements methods were deployed for corrosion analyzes under 3.5 wt % NaCl solution. Characterization and microstructure 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). A cogent improvement in the corrosion behavior of the Cr-ND coatings compared to pure chromium coatings and non-coated specimens were obtained due to the performed corrosion tests results.