The Study On Preparation And Oxidation Resistance Of Fecral Coatings

Oxidation corrosion of metals at high temperatures has driven the development of coating technology.The coating on the workpiece surface will improve the performance of the workpiece and prolong the service life of the workpiece.In this study,magnetron sputtering ion plating and multi-arc ion plating technology were used to modify FeCrAl coatings with different modulation periods and different compositions on the surface of 45 steel,Si,and molybdenum,respectively,by changing the workpiece carrier rotation speed and Cr target current.The microstructure,mechanical properties,electrochemical corrosion properties and high temperature oxidation resistance of the coatings were investigated.The effect of rotating speed and Cr target current on the microstructure and properties of the coating was analyzed.The high-temperature oxidation behavior and anti-oxidation mechanism of FeCrAl coating were also discussed.The results show that the FeCrAl coatings prepared in this experiment are composed of body-centered cubic lattice Fe-Cr solid solution,Al exists in the form of amorphous and solid solution to the lattice;in the magnetron sputtering coating,with the increase of workpiece speed,the surface roughness of the coating increases first and then decreases,the composition remains basically unchanged,the hardness of the coating decreases,and the binding force with the substrate increases significantly;under the multi-arc process,with the increase of the Cr target current,the Cr content in the coating gradually increases,and the droplet size on the surface decreases.The thickness of the coating increased from 8.32?m to 15.15?m.The hardness of the coating gradually decreased,and the coating and the substrate were well combined.Electrochemical corrosion of the coating in 3.5 wt%Na Cl solution showed that the corrosion resistance of the deposited coating was the best when the workpiece carrier rotation speed was 5r/min;Cr content had little effect on the corrosion resistance of the coating.The best electrochemical performance was obtained when the Cr target current was 1.0A.The high temperature oxidation resistance of FeCrAl coating is based on the formation of a dense protective oxide layer(Al₂O₃/Cr₂O₃)on the surface,which effectively slows down the further oxidation of the coating.When the Al content in the coating is low,the Cr₂O₃protective layer is mainly formed at high temperature,and the Cr content increases the oxidation resistance of the coating,but if the content is too high,the coating will crack at a high temperature,which will affect the coating to some extent.Layer structure and the formation of oxide film stability.