Corrosion resistance of nano ZrO2/Zn-Al-C coating in simulated geothermal water

Abstract

In order to improve the anti-corrosion performance of epoxy coatings, modified nano-ZrO2/Zn-Al-C epoxy resin composite coatings were prepared by using γ-aminopropyltriethoxysilane (KH-550) to improve the agglomeration phenomenon of nano-ZrO2 particles in combination with Zn-Al-C alloy powder. X-ray diffraction (XRD), Fourier infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM) were used to characterize the structural changes of nano-ZrO2 before and after the modification. With electrochemical AC impedance spectroscopy (EIS) and polarization curves (Tafel), the corrosion behavior of the composite coatings in simulated geothermal water environment was analyzed. The results show that the nano-ZrO2 surface is successfully grafted with KH-550; the number of corrosion scaling products on the surface of the composite coating is significantly reduced compared with the original sheet after full immersion in simulated geothermal water for 720 h; the self-corrosion current density is 6.113×10-10 (A·cm-2), and the electrochemical performance is good. The modified epoxy composite coating effectively utilizes the superior properties of nanomaterials and metallic materials, and its hardness and corrosion resistance are improved significantly, which provides a reference for the long-term use of epoxy coating in geothermal water environment.

Keywords

• geothermal water
• anti-corrosion coating
• nano zro2
• zn-al-c alloy powder
• epoxy resin