Effects of Cr–Si diffusion barrier layer on the oxidation resistance of NiCrAlY coating system with aluminized top layer

From National Research Council Canada

DOIResolve DOI: https://doi.org/10.1007/s11085-015-9604-x
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Name affiliation
  1. National Research Council of Canada. Aerospace
FormatText, Article
SubjectAluminum; Aluminum coatings; Coatings; Diffusion; Diffusion coatings; Multilayers; Oxidation; Oxidation resistance; Plasma spraying; Silicon; Co-deposited layer; Inward diffusion; Multi-layer-coating; NiCrAlY coating; Plasma sprayed; Si diffusion; Si layer; Spallation resistance; Diffusion barriers
Abstract
A multilayer coating, which consisted of a Cr–Si co-deposited layer as the diffusion barrier, a plasma sprayed NiCrAlY middle layer, and an aluminized top layer, was developed. During the aluminizing treatment, Cr in the NiCrAlY layer was released as the γ/γ′ structure of this layer transformed to the β phase. The released Cr was inhibited by the inner Cr–Si layer to diffuse into the substrate, and a Cr layer eventually formed over the Cr–Si layer. The Cr layer impeded the inward diffusion of Al due to the low solubility of Al in the Cr layer so that more Al atoms remain in the coating and contributed to the oxidation resistance of the coating. The multilayer coating exhibited better oxidation and spallation resistance than coatings without a Cr–Si layer, at least at 1050 °C for up to 1000 h.
Publication date
In
  • Oxidation of Metals (11 December 2015): 1–18.
LanguageEnglish
Peer reviewedYes
NPARC number21277358
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Record created2016-03-09
Record modified2020-04-22
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