Oxidation Behavior of LPPS MCrAlY Coatings at High Temperature: Part I TGO Growth and β Phase Depletion

Abstract:

MCrAlY can be used as bond coats for thermal barrier coatings (TBCs) with good ductility and excellent resistance against high temperature oxidation and hot corrosion. The behavior of the thermally grown oxide (TGO) scale formed at the MCrAlY coatings plays a key role on the oxidation resistance. In this paper, the oxidation kinetic curves of a MCrAlY coating at 900~1000 °C were obtained by measuring the thickness of the TGO scales. The curves basically conveyed parabolic laws, indicating a diffusion-controlled mechanism of the TGO growth. The thickness of TGO was positively correlated with the consumption of β phase during the early stage of the oxidation processes. After about the half-life of the β phase consumption, the depletion of the β phase significantly accelerated, which was caused by coating-substrate interdiffusion. In addition, the microstructure of the TGO was analyzed

• Periodical: Materials Science Forum (Volume 1035)
• Pages: 539-544
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.1035.539
• Online since: June 2021
• Authors: Zhao Ran Zheng*, Kang Yuan
• Keywords: CPZ, MCrAlY, Oxidation, TGO

References

[1] W. Brandl, H.J. Grabke, D. Toma, and J. Krüger, The oxidation behaviour of sprayed MCrAY coatings, Surf. Coat. Techn., 1996, 86, pp.41-47.

DOI: 10.1016/s0257-8972(96)03039-3

[2] M.J. Pomeroy, Coatings for gas turbine materials and long term stability issues. Materials & Design, 2005. 26(3). 223-231.

DOI: 10.1016/j.matdes.2004.02.005

[3] W. Braue, K. Fritscher, et al., Nucleation and Growth of Oxide Constituents on NiCoCrAlY Bond Coats during the Different Stages of EB-PVD TBC Deposition and Upon Thermal Loading., Materials Science Forum 461-464, 899-906.

DOI: 10.4028/www.scientific.net/msf.461-464.899

[4] W. Brandl, H.J. Grabke, et al., The oxidation behaviour of sprayed MCrAly coatings., 86, 41-47 (1996).

DOI: 10.1016/s0257-8972(96)03039-3

[5] Y.H. Sohn, J.H. Kim, et al., Thermal cycling of EB-PVD/MCrAlY thermal barrier coatings: I. Microstructural development and spallation mechanisms., Surf. Coat. Tech. 146-147, 70-78.

DOI: 10.1016/s0257-8972(01)01478-5

[6] D.Naumenko, V.Shemet, L. Singheiser, and W.J. Quadakkers, Failure mechanisms of thermal barrier coatings on MCrAlY-type bond coats associated with the formation of he thermally grown oxide. Journal of Materials Science, 2009. 44(7). 1687-1703.

DOI: 10.1007/s10853-009-3284-3

[7] U. Schulz, M. Menzebach, C. Leyens, and Y.Q. Yang, Influence of substrate material on oxidation behavior and cyclic lifetime of EB-PVD TBC systems. Surface & Coatings Technology, 2001. 146. 117-123.

DOI: 10.1016/s0257-8972(01)01481-5

[8] W. Brandl, H.J. Grabke, D. Toma, and J. Kruger, The oxidation behavior of sprayed MCrAlY coatings. Surface & Coatings Technology, 1996. 86(1-3). 41-47.

DOI: 10.1016/s0257-8972(96)03039-3

[9] W.G. Sloof and T.J. Nijdam, On the high-temperature oxidation of MCrAlY coatings. 45 International Journal of Materials Research, 2009. 100(10). 1318-1330.

DOI: 10.3139/146.110201