Morphology and phase structures of CW laser-induced oxide layers on iron surface with evolving reflectivity and colors
| Autor: | Chenghua Wei, Taotao Wu, Wu Lixiong, Lijun Wang, Min-bo He, Zhou Menglian |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Diffraction
Materials science Oxide Analytical chemistry General Physics and Astronomy 02 engineering and technology 010402 general chemistry 01 natural sciences law.invention symbols.namesake chemistry.chemical_compound Optics law Fiber laser Magnetite business.industry Surfaces and Interfaces General Chemistry Hematite 021001 nanoscience & nanotechnology Condensed Matter Physics Laser 0104 chemical sciences Surfaces Coatings and Films chemistry visual_art symbols visual_art.visual_art_medium Crystallite 0210 nano-technology Raman spectroscopy business |
| Zdroj: | Applied Surface Science. 387:1183-1187 |
| ISSN: | 0169-4332 |
| DOI: | 10.1016/j.apsusc.2016.06.084 |
| Popis: | Laser-induced oxidation will change the laser reflectivity and color features of metal surface. Both changes can be theoretically calculated based on the oxidation kinetics and the optical constants of oxides. For the purpose of calculation, the laser-induced oxidation process of pure polycrystalline iron was studied. Samples with various color features were obtained by continuous wave Nd:YAG fiber laser (1.06 μm) irradiation depending on progressive durations in the intensity of 1.90 W/cm2. The real-time reflectivity and temperature were measured with integral sphere and thermocouples. The irradiated surface morphology and phase structures were characterized by microscope, X-ray diffraction and Raman spectrum. It was found that the first formed magnetite made the surface reflectivity decline rapidly and caused the “positive feedback” effect because of molecular absorption. The later formed hematite oscillated the reflectivity by interference effect. The oxide films were thin, orientated and badly crystallized. The oxidation process was influenced by the grain orientation of the metal substrate. These results made the mechanism of laser-induced oxidation of iron clear and provided available experimental data for accurate modeling of the oxidation kinetics. |
| Databáze: | OpenAIRE |
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