Study on Preparation and Mechanical Properties of Superhydrophobic Ni/TiO₂ Composite Coating on Surface of Stainless Steel

Abstract

In order to improve the antifouling and corrosion resistance of stainless steel, a superhydrophobic Ni/TiO2 composite coating was successfully prepared on the surface of stainless steel by one - step electrodeposition technology and fluorination modification technology. The effect of current density on the surface morphology of Ni coating was investigated, and a Ni coating with a rough petal - like structure was fabricated when the current density was 9 A/dm2. Subsequently, a co - deposition method was adopted to acquire Ni/TiO2 composite coating on the surface of stainless steel using such constant current density, and then the acquired coating was treated with fluorination modification to form a superhydrophobic composite coating. Moreover, the surface morphology, chemical composition and crystal structure of the prepared coating were studied through field emission scanning electron microscopy (FESEM), energy dispersive spectroscopy (EDS) and X - ray diffraction (XRD). The contact angle test results showed that the modified Ni/TiO2 composite coating possessed superhydrophobic property with a contact angle of 159.2° and a sliding angle of 6.3°. The results of tape peeling test and abrasion test showed that the superhydrophobic composite coating had superior mechanical stability. Compared with bare stainless steel, the self - corrosion current density of the superhydrophobic composite coating decreased by two orders of magnitude, and the corrosion inhibition efficiency reached 98.4 %, exhibiting excellent corrosion resistance. Meantime, the superhydrophobic Ni/TiO2 composite coating also possessed good self - cleaning performance and could provide an effective protection for the substrate.

Keywords

• electrodeposition|fluorination modification|ni/tio2 composite coating|superhydrophobic|mechanical stability