ALBERT

Description: 〈p〉Publication date: 25 January 2019〈/p〉 〈p〉〈b〉Source:〈/b〉 Surface and Coatings Technology, Volume 358〈/p〉 〈p〉Author(s): Yankun Li, Minfang Chen, Wei Li, Qi Wang, Yansong Wang, Chen You〈/p〉 〈div xml:lang="en"〉 〈h5〉Abstract〈/h5〉 〈div〉〈p〉Micro-arc oxidation (MAO) as an environmentally friendly technology is used to produce ceramic film on metal surfaces to improve its corrosion properties, and the films quality is mainly affected by the electrolyte composition and electrochemical parameters, Here, to improve the corrosion property and wear-resisting of low carbon steel, a compact, corrosion resistant α-Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉 ceramic film was prepared on the surface of low carbon steel containing boron (10B21) by MAO. A Na〈sub〉2〈/sub〉SiO〈sub〉3〈/sub〉 and NaH〈sub〉2〈/sub〉PO〈sub〉4〈/sub〉 electrolyte system was designed with different content of Na〈sub〉2〈/sub〉CO〈sub〉3〈/sub〉 and Na〈sub〉2〈/sub〉B〈sub〉4〈/sub〉O〈sub〉7〈/sub〉. The ceramic layer produced with Na〈sub〉2〈/sub〉CO〈sub〉3〈/sub〉 and Na〈sub〉2〈/sub〉B〈sub〉4〈/sub〉O〈sub〉7〈/sub〉 showed improved corrosion resistance. The corrosion current density was 2.7 μA·cm〈sup〉−2〈/sup〉 and the impedance value reached 1900 Ω·cm〈sup〉2〈/sup〉. After 7 days of neutral salt spray corrosion, the corrosion rate of this sample coating reduced to 53 g·m〈sup〉−2〈/sup〉·h〈sup〉−1〈/sup〉. The influence mechanism is discussed. The cooperation of Na〈sub〉2〈/sub〉CO〈sub〉3〈/sub〉 and Na〈sub〉2〈/sub〉B〈sub〉4〈/sub〉O〈sub〉7〈/sub〉 in the electrolyte is more effectively regulated the ionization and chemical reactions of the MAO process, catalyzing the formation of α-Al〈sub〉2〈/sub〉O〈sub〉3〈/sub〉. The coating had a uniform thickness of 100 ± 10 μm, no gap between the coating and the substrate was observed, which indicated that the bonding state was good. Thus, the MAO ceramic layer prepared on low carbon steel surface increases the service life of iron and steel components effectively, which can significantly expand its application in more fields.〈/p〉〈/div〉 〈/div〉