Effect of annealing on microstructure evolution and corrosion resistance of an amorphous Cr-Al-C coating. (January 2021)

• Record Type: Journal Article
• Authors: Zhang, Zerong; Qian, Yuhai; Xu, Jingjun; Zuo, Jun; Li, Meishuan
• Is Part Of: Corrosion science. Volume 178(2021)
• Publication Date: 2021-01
• Subjects: MAX phase -- Amorphous coating -- Annealing process -- Corrosion resistance -- Passive film; Corrosion and anti-corrosives -- Periodicals; 620.11223
• DOI: 10.1016/j.corsci.2020.109062
• Languages: English
• ISSNs: 0010-938X

Abstract

Highlights: Amorphous Cr-Al-C coating firstly transformed into solid solution, and then into Cr2 AlC MAX phase during annealing. All the coatings exhibited passivation behaviors, and amorphous coating possessed the lowest passive current density. All the passive films exhibited p-type semiconductor characteristics. The passive film on the amorphous coating was most protective for containing a relatively high content of Cr2 O3 . Abstract: The microstructure evolution of an amorphous Cr-Al-C coating prepared by magnetron sputtering was investigated. With increasing annealing temperature, three kinds of coatings, including amorphous coating, partially crystallized coating ((Cr, Al)2 Cx solid solution), and fully crystallized coating (Cr2 AlC MAX phase), were obtained. The electrochemical measurements in 3.5 wt. % NaCl solutions indicated that all of the coatings exhibited passivation behaviors, and amorphous coating possessed the lowest passive current density. All the passive films exhibited p-type semiconductor characteristics, and the passive film on amorphous coating provided the best protection due to the presence of a relatively high content of Cr2 O3 .