The Coating Process of Black Chromium Used on Steel Substrates of Solar Power Plants Obtained by Optimized Electroplating Black Chromium Bath

This paper discusses the application of black chromium coating on steel substrates applicable in solar power plants obtained from the optimum electroplating black chromium bath. Black chromium is one type of selective coatings that used usually in solarpower plants. As absorption and thermal radiation are related to black surface and undercoats respectively, the thickness of absorption layers should be lower than infrared wavelength so that undercoat shows its appropriate optical properties and decreasethe thermal radiation. Since copper have lowest thermal radiation which is due to their high conductivity and also their smooth and polished surfaces, in this research copper selected as an undercoat. The result proves that Electrodeposition of copper on steelsubstrates from sulfate baths is possible. Electrodeposition was carried out at room temperature. The plating time and concentration was variable to find the best coat at minimum amount of copper sulfate. Then Electrodeposition of black chromium was also carried out at different time, temperature and composition of black chromium bath. Adjusting the pH level was not a matter of importance after bath preparations. Adhesion and Uniformity of the coatings were investigated by Scaning Electron Microscopy (SEM).