Study of the effect of laser treatment on the initial oxidation behaviour of Al‐coated NiCrAlY bond‐coat. (18th October 2013)

• Record Type: Journal Article
• Authors: Zhu, C.; Javed, A.; Li, P.; Liang, G. Y.; Xiao, P.
• Is Part Of: Surface and interface analysis. Volume 45:Number 11/12(2013:Nov.)
• Page Start: 1680
• Page End: 1689
• Publication Date: 2013-10-18
• Subjects: NiCrAlY bond‐coat -- Al film -- laser treatment -- oxidation resistance; Surfaces (Physics) -- Periodicals; Surface chemistry -- Periodicals; Thin films -- Periodicals; 541.33
• DOI: 10.1002/sia.5307
• Languages: English
• ISSNs: 0142-2421

Abstract

Abstract : 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‐Al2 O3 /Cr2 O3 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‐Al2 O3, NiO, Cr2 O3 and NiCr2 O4 spinel oxides was observed to be suppressed due to the preformed α‐Al2 O3 scale during initial oxidation on the surface of laser pre‐oxidized Al/NiCrAlY bond‐coat. Copyright © 2013 John Wiley & Sons, Ltd.