Oxidation behaviour at 1123 K of AISI 304-Ni/Al-Al2O3/TiO2 multilayer system deposited by flame spray
| Autor: | I. Cervera, M. S. Damra, J. J. Saura, K. A. Habib, C. Ferrer |
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| Rok vydání: | 2011 |
| Předmět: |
Materials science
Precipitation (chemistry) Scanning electron microscope Metallurgy Metals and Alloys Analytical chemistry engineering.material Intergranular corrosion Condensed Matter Physics Coating visual_art Materials Chemistry engineering visual_art.visual_art_medium Ceramic Physical and Theoretical Chemistry Thermal spraying Layer (electronics) Deposition (law) |
| Zdroj: | Revista de Metalurgia. 47:126-137 |
| ISSN: | 1988-4222 0034-8570 |
| Popis: | The oxidation behaviour of alumina/titania (97/3, 87/13 and 60/40) ceramic coatings using a Ni-Al coupling layer was studied in a thermobalance. Both layers were deposited on an AISI 304 stainless steel base metal by the flame spray technique. The coated steel was heated from room temperature to 1,123 K at 40 K min –1 , oxidized in air for 50 h, and then cooled to room temperature at 40 K min –1 . The mass gain was mainly attributed to the oxidation of Ni-Al coupling layer. Kinetic laws, DW·S –1 (mg.mm –2 ) vs. time (hours) were close to a parabolic plot for each sample. Surface composition of ceramic top layer and the cross section of multilayer system were analysed using a wide range of experimental techniques including Scanning Electron Microscopy (SEM), equipped with a link energy dispersive X-Ray spectroscopy (EDX) and X-Ray diffraction (XRD) before and after the oxidation process. Coatings 97/3 and 87/13 presented a stable structure after flame spray deposition and they did not evolve with the oxidation process, while most of the 60/40 coating changed to a metastable structure after deposition and to a more stable structure after oxidation with high micro-cracks content. SEM and EDX microanalysis of the cross-sections showed that significant oxidation and a weak intergranular precipitation had been produced in the coupling layer and on the stainless steel base metal, respectively. |
| Databáze: | OpenAIRE |
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