EPRI-2013 ManuscriptASuzuki Final.pdf (374.23 kB)
Formation of diffusion zones in coated Ni-Al-X ternary alloys and Ni-based superalloys
conference contributionposted on 2014-03-12, 15:06 authored by A.S. Suzuki, Geoff West, Rachel ThomsonRachel Thomson
Coatings are an essential part of the materials system to protect the turbine blades from oxidation and corrosive attack during service. Inter-diffusion of alloying elements between a turbine blade substrate and their coatings is a potential concern for coated turbine blades at ever increasing operating temperatures because this can cause the formation of undesirable Secondary Reaction Zones (SRZs), which may degrade the mechanical properties of coated Ni-based superalloys. Understanding the effects of each element on the SRZ formation is essential in order to understand both the mechanism and inter-diffusion behaviour between coatings and substrates. In this research, a number of simpler aluminized ternary Ni-Al-X (where X is Co, Cr, Re, Ru or Ta) alloys were investigated in order to elucidate the separate effects of each element on the microstructural evolution, especially at the coating/substrate interface. The aluminized ternary alloys developed distinctive diffusion zones, depending on the third alloy element, ‘X’. Specifically, it has been found that both Ni-Al-Re and Ni-Al-Ta alloys developed a continuous SRZ-like diffusion layer. This diffusion zone persisted in the Ni-Al-Re alloys after high temperature exposure, indicating that Re has a stronger effect on SRZ formation than Ta.
This research was supported by the Japan Society for the Promotion of Science (JSPS) Postdoctoral Fellowship for Research Abroad scheme and the Department of Materials, Loughborough University.
- Aeronautical, Automotive, Chemical and Materials Engineering
CitationSUZUKI, A.S., WEST, G.D. and THOMSON, R.C., 2014. Formation of diffusion zones in coated Ni-Al-X ternary alloys and Ni-based superalloys. IN: Gandy, D. and Shingledecker, J. (eds). Advances in Materials Technology for Fossil Power Plants: Proceedings from the Seventh International Conference (EPRI 2013), 22nd-25th October 2013, Waikoloa, Hawaii, USA. ASM International, pp. 371 - 381.
Publisher© ASM International
- AM (Accepted Manuscript)
NotesCopyright 2014 ASM International, www.asminternational.org. This article was published in Advances in Materials Technology for Fossil Power Plants: Proceedings from the Seventh International Conference and is made available as an electronic reprint with the permission of ASM International. One print or electronic copy may be made for personal use only. Systematic or multiple reproduction, distribution to multiple locations via electronic or other means, duplications of any material in this article for a fee or for commercial purposes, or modification of the content of this article is prohibited.