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.

抽象的

双辉等离子体表面合金化工艺（DGP）是用于制造热障涂层的新兴替代技术。尽管DGP方法具有梯度冶金结合和厚度可控性等优点，但与结合层的电子束物理气相沉积和等离子喷涂技术相比，DGP方法广为人知。本文是对该技术在钛合金上制备梯度MCrAlY粘结涂层的应用的初步研究，重点是在750、850和950°C下的氧化性能。在这项研究中，通过DGP成功地在γ-TiAl合金上合成了梯度MCrAlY键合涂层。所沉积的涂层由γ'-Ni系₃的Al，γ-TiAl基，ALCR ₂和σ-NiCoCr。沉积后的涂层可以承受的最大载荷为60N。由于形成了多层氧化皮，MCrAlY涂层的抗氧化性能比裸TiAl合金好得多。还讨论了进一步优化此类MCrAlY涂层的研究机会。