Characterisation and oxidation behaviour of plasma surface alloyed on γ-TiAl alloy

ABSTRACT

The double glow plasma surface alloying process (DGP) is an emerging alternative technology for fabricating thermal barrier coating. In spite of its merits such as gradient metallurgical bond and thickness controllability, DGP method is less well known than electron beam-physical vapour deposition and plasma spraying technique for the bond coatings. This paper serves as a preliminary study into the use of this technology for preparation of gradient MCrAlY bond coating on titanium alloys, with a focus on the oxidation performance at 750, 850 and 950°C. In this study, a gradient MCrAlY bond coating was successfully synthesised on γ-TiAl alloy by DGP. The as-deposited coating was composed of γ′-Ni₃Al, γ-TiAl, AlCr₂ and σ-NiCoCr. The maximum load that the as-deposited coating could bear was 60 N. The MCrAlY coating exhibited much better oxidation resistance than the bare TiAl alloy due to the formation of multilayer oxide scales. The research opportunities for further optimisation of this type of MCrAlY coatings are also discussed.

KEYWORDS:

• Coating materials
• metals and alloys
• corrosion
• kinetics

Acknowledgments

The work presented in the paper was supported by the Priority Academic Program Development of Jiangsu Higher Education Institutions, the Natural Science Foundation for Young Scientists of Jiangsu Province, China (Grant No.BK20140819), the Aeronautical Science Foundation of China (Grant No. 2016ZF52056), the China Scholarship Council (Grant No. 201706830071, award to Xiaohu Chen for 1 year’s study abroad at the Carleton University) and the Fundamental Research Funds for the Central Universities and the Foundation of Graduate Innovation Center in NUAA (Grant No. kfjj20170606).

The raw/processed data required to reproduce these findings cannot be shared at this time due to technical or time limitations.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the the Priority Academic Program Development of Jiangsu Higher Education Institutions; the Jiangsu Province Graduate Cultivation Innovative Project [No. KYLX16_0347]; the Foundation of Graduate Innovation Center in NUAA [Grant No. kfjj20170606]; the Aeronautical Science Foundation of China [Grant No. 2016ZF52056]; the China Scholarship Council [Grant No. 201706830071]; the Natural Science Foundation for Young Scientists of Jiangsu Province, China [Grant No.BK20140819].