Electrochemical Deposition Of Carbon Film On Stainless Steel In Molten Salt

Carbon film has attracted a lot of interests in some fields, because it exhibits unique physical, chemical properties. The most frequently used methods for the deposition of carbon film are physical vapor deposition (PVD) and chemical vapor deposition (CVD). But these methods have some disadvantages, such as poor adhesion of carbon film due to its high residual stresses. To improve the quality of carbon film, carbon film is prepared by an electrochemical route in the molten KCl-LiCl in this paper. The oxidation behavior of304stainless steel is investigated under high temperature. Carbons films are deposited on substrates treated by different conditions and an optimal pre-treatment of stainless steel substrate is determined. The growth of carbon film on substrate is also discussed. Raman spectroscopy was used to examine the chemical bond in the film. The component and structure of oxide scale and carbon film on substrates were analyzed by scanning electron microscopy. The adhesion strength of carbon film on stainless steel was evaluated using scratch tester.The oxidization and electro-deoxidation of stainless steel substrate are important pre-treatment for deposition of continuous carbon film. The macro-, micro-roughness of the substrate are enhanced after the pre-treatment. The adhesion and depth of oxide scale, and the particle size of oxides are influenced by temperature and time of the oxidation. These strongly affect integrity and adhesion of the deposited carbon film. Carbon film is composed of’quasi-spherical’carbon particles, which predominantly comprise of sp2-hybridized carbon. The carbon particles are gradually becoming bigger from the surface of stainless steel to the surface carbon film with increasing of the amount of carbon deposited, and their adhesion getting poorer in this process.