Study the Effect of Surface Parameters Variation on the Corrosion Behavior of Thin Chromium Layer on Modified Titanium
Arvin Taghizadeh Tabrizi, Hossein Aghajani, Farhad Farhang Laleh
Abstract
In this study, a thin chromium layer was applied on pure titanium substrate in a Sargent bath including 250 g/L chromic acid and 2.5 g/L sulfuric acid at 60°C utilizing a different current density of 30, 40, 50, and 60 A/dm2 for 15 and 30 min which were chosen based on the simulation results achieved from COMSOL Multiphysics software. To characterize the properties of achieved layers, field emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM) was carried out to evaluate the surface morphology of the deposited layer. Also, to investigate the corrosion properties of samples, electrochemical impedance spectroscopy (EIS) and polarization test were performed at room temperature and in standard 3.5 wt % NaCl solution. Although the intrinsic microcracks network of chromium coating, the corrosion behavior of the coated samples was improved remarkably. All samples corrosion resistance about 99.4% in comparison of pure titanium and the best resistance obtained in sample coated in 15 min at 30 A/dm2. The relation between the corrosion resistance with surface parameters was studied and it is shown that corrosion resistance is in relation to maximum peak height, maximum height, and the slope of the asperities.