Investigation of the bond coats for thermal barrier coatings on Mg alloy

• Published in: Applied surface science Vol. 265; pp. 264 - 273
• Main Authors: Fan, Xizhi, Zou, Binglin, Gu, Lijian, Wang, Chunjie, Wang, Ying, Huang, Wenzhi, Zhu, Ling, Cao, Xueqiang
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.01.2013; Elsevier
• Subjects: Bond coat; Bonding; Coating; Condensed matter: structure, mechanical and thermal properties; Corrosion; Corrosion resistant alloys; Deposition; Disordered solids; Exact sciences and technology; Intermetallic compounds; Intermetallics; Magnesium base alloys; Mg alloy; Oxidation; Oxidation resistance; Physics; Plasma spraying; Powders, porous materials; Stability; Structure of solids and liquids; crystallography; Thermal barrier coatings; Oxidation; Stability; Corrosion; Mg alloy; Plasma spraying; Bond coat; Powders; Magnesium alloys; Plasma arc spraying; Thermal barrier coatings
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2012.10.192

▸ Bond coats of Al@Ni, MCrAlY(M=Co, Ni) and Ni@Al for Mg alloy were investigated. ▸ The bond coats had moderate TECs (13–15×10−6K−1). ▸ The structure of original powders affected the properties of the sprayed bond coats. ▸ MCrAlY bond coat had excellent oxidation resistance at 400–500°C. ▸ MCrAlY bond coat had excellent corrosion resistance in 3.5% NaCl solution. ▸ MCrAlY was demonstrated as the most appropriate bond coat for TBCs on Mg alloy. Bond coats play a significant role in manipulating the stability of 8YSZ thermal barrier coatings (TBCs) deposited on Mg alloy. In this study, different bond coats from the Al@Ni, Ni@Al and MCrAlY (M=Co, Ni) powders were prepared on the Mg alloy by atmospheric plasma spraying. The spraying behavior of the powders, the microstructure, oxidation and corrosion resistance of the produced bond coats were investigated to find the positive bond coat for TBCs on Mg alloy. Results indicate that the composition and structure of original powders affect the structure and properties of the sprayed bond coats. For the candidate bond coats, the MCrAlY bond coat is demonstrated as the most appropriate one for 8YSZ TBCs deposited on Mg alloy substrate, which is mainly attributed to its moderate thermal expansion match and excellent corrosion and oxidation resistance under the simulated corrosion and relatively high temperature conditions.