Electrochemical Properties of Fe-Based Amorphous Metallic Coatings in Aqueous Media

Abstract

Coating as an effective corrosion barrier for various industrial application is one of the major research trend in electrochemistry. Many types of coating materials and techniques have been suggested and a high-velocity oxy-fuel (HVOF) technique has adequate potential. Fe-based amorphous metallic coating (AMC) is a non-crystalline alloy coating with spatially dispersed nanocrystalline structure. As they are known as an effective anti-corrosion and anti-wear resistance, some research groups have figured out their corrosion behavior in corrosive environments. In this study, we experimentally demonstrated the corrosion behavior of Fe-based AMC in seawater and alkaline medium environments using various electrochemical tests including linear sweep voltammetry (LSV) and electrochemical impedance spectroscopy (EIS). Fig. 1. Displays the powder morphology of Fe-based AMC feedstock material. Spherical shape with ca. 30 um size particles can be observed. The chemical composition is 54.05Fe-18.31Cr-11.34W-12.5Mo-2.8Mn. After the spray process, surface and cross section morphologies are analyzed by SEM (Fig. 2). Fig. 3. Displays the corrosion behavior of the substrates and the coatings in seawater and alkaline media, respectively. The results indicates that corrosion resistance of Fe-based AMC is not remarkable in both media. Fig. 4. Also displays the corrosion resistance is lower and double layer capacitance is higher compared to those of the substrates. Thus, likewise to other research results, the as-sprayed Fe-based AMC exhibits less corrosion resistance compared to carbon steels. However, their promising potential in high-temperature alkaline media and flowing conditions will be figured out as our future works. Figure 1