Effect of pore content and pH on the corrosion behavior of hydrophobic ceramic coatings

Abstract

In this paper, superhydrophobic ceramic coatings were successfully prepared on stainless steel substrates (S304) by sol-gel method, and the effects of pore content and pH conditions on the corrosion resistance of hydrophobic ceramic coatings were studied. As the porosity increases, the contact angle of the coating increases. Among them, the contact angles of the coatings with 15% and 20% porosity in different pH solutions are all greater than 150 • , achieving superhydrophobic surfaces. The contact angle results before and after corrosion show that the solution with a higher pH has a greater damage to the hydrophobicity of the coating. The corrosion resistance of the coatings was evaluated comparatively from polarization curves and electrochemical impedance spectroscopy. As the hydrophobicity improves, the corrosion resistance of the hydrophobic ceramic coating is enhanced. The impedance moduli at .01 Hz of the coating are 1.04 × 10 3 times (pH 4), .13 × 10 3 times (pH 7), and .74 × 10 3 times (pH 10) of the bare steel, respectively. With the increase of pH, the corrosion resistance of hydrophobic ceramic coatings decreases, because OH − in the corrosion solution is more easily adsorbed on the surface of the coating, thereby destroying the long hydrophobic chains.

Effects of Ti ion deposition on corrosion resistance of WE43 alloy

“…Figure 7 is EIS of WE43 alloy and alloys with different Ti ion deposition times in SBF solution. It can be seen from Figure 7(A) that the capacitive arc radius of the Ti800 alloy is the largest, indicating that the alloy has better corrosion resistance 29,30 . Following Ti1200 alloy, its corrosion resistance is second only to Ti800 alloy.…”

“…It can be seen from Figure 7(A) that the capacitive arc radius of the Ti800 alloy is the largest, indicating that the alloy has better corrosion resistance. 29,30 Following Ti1200 alloy, its corrosion resistance is second only to Ti800 alloy. However, the capacitance arc radius of Ti400 and Ti1800 alloys is not very different, and the corrosion rate of the alloy increases due to more surface defects.…”

Insight into Microstructure Evolution and Corrosion Mechanisms of K2ZrF6/Al2O3-Doped Hot-Dip Aluminum/Micro-Arc Oxidation Coatings

“…This suggests that an appropriate amount of K 2 ZrF 6 /Al 2 O 3 powder adequately fills the volcano-like micropores on the micro-arc oxidation ceramic coating, reducing the number and size of these pores [56,61,62]. Moreover, the formed phases such as Al 2 O 3 and ZrO 2 can obstruct the erosion of corrosive ions, enhancing the corrosion resistance of the ceramic coating [63,64].…”

Adhesion Strength and Anti-Corrosion Performance of Ceramic Coating on Laser-Textured Aluminum Alloy

“…This suggests that this is an appropriate voltage to reduce the number and size of pores. Moreover, the formed oxides such as Al 2 O 3 and TiO 2 can obstruct the erosion of corrosive ions, enhancing the corrosion resistance of the ceramic coating [33,34].…”

“…Coatings 2023, 13, x FOR PEER REVIEW 9 o such as Al2O3 and TiO2 can obstruct the erosion of corrosive ions, enhancing the corros resistance of the ceramic coating [33,34]. Sandblasting is widely regarded as a method of surface treatment, but noise and d from sandblasting may be detrimental to the environment.…”