Corrosion resistance of Fe sub(2)O sub(3)-Cr sub(2) O sub(3) artificial passive films formed with LP-MOCVD

• Published in: Metals and materials international 2002-04, Vol.8 (2), p.203-209
• Main Authors: Kim, Hyun-Soo, Yoon, Jae-Hong, Shin, Kee-Sam, Sugimoto, Katsuhisa
• Format: Article
• Language: English
• Subjects: Corrosion resistance; Crystal structure; Crystallinity; Deposition; Dissolution; Iron; Low pressure; Reduction
• ISSN: 1598-9623
• DOI: 10.1007/BF03027019

Fe sub(2)O sub(3)-Cr sub(2)O sub(3) artificial passive films were formed with a low pressure MOCVD technique using iron (III) acetylacetonate and chromium (III) acetylacetonate. The relationships between the crystal structure, the chemical state of the constituent elements, and the corrosion resistance of the films were examined in acid solutions. The films deposited above 300 degree C hardly dissolved in 1.0 M HCl and those deposited below 250 degree C, however, easily dissolved in the same solution. The dissolution rate of the films in solution increased with decreasing substrate temperature. When polarized cathodically in 1.0 M H sub(2)SO sub(4), the films deposited below 250 degree C dissolved due to the reduction of the Fe sub(2)O sub(3) component in the films. The reduction of the Fe sub(2)O sub(3) component was, however, suppressed on the films deposited above 300 degree C. Therefore, with increasing crystallinity and the amount of M-O type chemical bonds, the corrosion resistance of the films increases in HCl and H sub(2)SO sub(4) solutions.