Silica Sol-Gel Film on Bright Nickel Plating of Steel A3 Substrate

Abstract

At present, ceramic coatings have attracted more and more attention for its good resistance, good chemical stability, and high temperature resistant, hydrophobic and other properties. SiO2 sol was prepared by chelated silicon powders to prepare SiO2 sol-gel film on the nickel plating layer. Pre-plating ordinary bright nickel-plating layer and composite bright nickel plating layer on the iron surface in advance, research some properties such as abrasion resistance, porosity, and NaCl solution soak test of SiO2 sol-gel films by changing the times of immersing SiO2 sol and baking temperature after immersing. The results show that: The time of emerging rust points for sol-gel coating on composite bright nickel-plated is much longer than that on ordinary bright nickel-plated in salt water soak test. The porosity of sol-gel coatings on composite bright nickel-plated is lower than that on ordinary bright nickel-plated. When the drying temperature is at 400°C or 500°C, the porosity rate is zero for the composite bright nickel without coatings or coated with any times of sol. It can improve wear resistance of the composite bright coating when immersing SiO2 sol at 500°C for 3 to 5 times. Porosity of SiO2 sol-gel coatings on the ordinary bright nickel layer is zero when baking at 500°C, immersing 3 times or more than 3 times. The best drying temperature is at 500°C, the best immersing times is 4 times to obtain better corrosion resistance for the bright nickel deposits. The color of the better appearance for a film is rainbow, its drying temperature of 500°C, immersing 4 times.