The effect of MAO processing time on surface properties and low temperature infrared emissivity of ceramic coating on aluminium 6061 alloy
| Autor: | Mohannad M.S. Al Bosta, Hsi-Hsin Chien, Keng-Jeng Ma |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
education.field_of_study
Materials science Infrared Population chemistry.chemical_element Condensed Matter Physics Cristobalite Atomic and Molecular Physics and Optics Electronic Optical and Magnetic Materials chemistry Aluminium visual_art visual_art.visual_art_medium Emissivity Surface roughness Ceramic Fourier transform infrared spectroscopy Composite material education |
| Zdroj: | Infrared Physics & Technology. 60:323-334 |
| ISSN: | 1350-4495 |
| DOI: | 10.1016/j.infrared.2013.06.006 |
| Popis: | MAO ceramic coatings were prepared on aluminium 6061 surfaces at different treating durations (10, 20, ... 60 min), using alkali silicate electrolyte and pulsed bipolar current mode. The surface microstructures and properties were studied using SEM, XRD, EDX and a surface roughness tester. Image-Pro Plus and MATCH! softwares were used to analyze SEM micrographs and XRD results, respectively. The infrared emissivities of the ceramic coatings were measured at the 70 °C using FTIR spectrometer. We found a linear correlation between the volcano-like area and the surface roughness. The compositions and phases were associated with the volcano-like population and area. The curve of IR spectral emissivity was influenced by surface roughness, γ-alumina, sillimanite and cristobalite phases. The emissivity was enhanced by the surface roughness in the ranges 4.0–9.6 μm and 10.5–14.8 μm. In the range 7.0–8.0 μm, α-alumina and sillimanite phases enhanced the emissivity, while the cristobalite has a negative impact to the emissivity. A negative contributions were found for α-alumina in the region 9.6–16.0 μm and for the surface thickness in the region 15.0–16.0 μm. Overall, the average of long wave infrared (LWIR) emissivity ranged from 87.05% to 91.65%. |
| Databáze: | OpenAIRE |
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