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Study of the effect of laser treatment on the initial oxidation behaviour of Al‐coated NiCrAlY bond‐coat
Author(s) -
Zhu C.,
Javed A.,
Li P.,
Liang G. Y.,
Xiao P.
Publication year - 2013
Publication title -
surface and interface analysis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.52
H-Index - 90
eISSN - 1096-9918
pISSN - 0142-2421
DOI - 10.1002/sia.5307
Subject(s) - materials science , nichrome , metallurgy , microstructure , spinel , composite material
In this study, the initial oxidation behaviour of laser‐treated Al/NiCrAlY bond‐coat is investigated. Two approaches, (i) Al film sputtering on the surface of bond‐coat and (ii) laser treatment, have been taken to enhance the oxidation resistance of NiCrAlY bond‐coat. Experimental results showed that after laser treatment, the Al/NiCrAlY bond‐coat exhibited a columnar dendritic microstructure without cracks and voids. A dense and continuous α‐Al 2 O 3 /Cr 2 O 3 multilayer was found to form on the bond‐coat surface. Results on the cyclic oxidation at 1200 °C (for time ≤ 204 h) revealed that the laser‐treated Al/NiCrAlY bond‐coat exhibited better oxidation resistance compared to as‐sprayed NiCrAlY, Al/NiCrAlY and laser‐remelted NiCrAlY bond‐coat. The formation of θ‐Al 2 O 3 , NiO, Cr 2 O 3 and NiCr 2 O 4 spinel oxides was observed to be suppressed due to the preformed α‐Al 2 O 3 scale during initial oxidation on the surface of laser pre‐oxidized Al/NiCrAlY bond‐coat. Copyright © 2013 John Wiley & Sons, Ltd.