Electrodeposition of NiCrAl(Y) Coatings with High Contents of Cr and Al and Their Oxidation Resistance

• Main Authors: ZHEN Huijuan, TIAN Lixi, DONG Zhihong, PENG Xiao
• Format: Article
• Language: zho
• Published: Journal of Aeronautical Materials 2018-04-01
• Series: Journal of Aeronautical Materials
• Subjects: NiCrAl(Y); high temperature oxidation; electrodeposition; electrophoretic deposition; nanocomposite coating
• Online Access: http://html.rhhz.net/CHXB/html/2018-2-52.htm

NiCrAlY coatings have been widely employed as the coatings to risist high temperature oxidation, hot corrosion and also the bond coat （BC） under thermal barrier coatings （TBCs）. High quality NiCrAlY coatings are currently always manufactured by means of physical vapor deposition （PVD）. This work prepared new NiCrAl nanocomposite coatings through electrodeposition of Ni into a porous CrAl nanoparticle layer pre-deposited electrophoretically on a metallic substrate. Microstructural observation shows that the as-deposited NiCrAl coatings, where the CrAl nanoparticles with the maximum mass percentage reaching 35 are uniformly dispersed, are dense and well bonded to the substrate. Oxidation in air at 1000 ℃ shows that the NiCrAl coatings can “smartly” grow a protective scale of either Cr₂O₃ or Al₂O₃, depending on the ratio of the content of Cr to Al which can be controlled during electrophoretic deposition. In the meantime, no spallation occurs even though the coatings oxidized for hundreds of hours.It is implying that the NiCrAl coatings are as good as the NiCrAlY coatings prepared by PVD in resistance to high temperature oxidation. This work paves a new way for manufacturing high quality NiCrAl（Y） coatings employed as overlay coat and BC, through electrodeposition with the merits of ease of fabrication and low cost as well as high efficiency.