Laser-assisted growth of microstructures on spatially confined substrates
| Autor: | G. A. Shafeev, S.I. Dolgaev, Alexander V. Simakin, N A Kirichenko |
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| Rok vydání: | 2007 |
| Předmět: |
Materials science
business.industry Capillary action General Physics and Astronomy Pulse duration Surfaces and Interfaces General Chemistry Condensed Matter Physics Laser Thermal conduction Molecular physics Surfaces Coatings and Films law.invention Surface tension Optics law Boundary value problem business FOIL method Melt flow index |
| Zdroj: | Applied Surface Science. 253:7987-7991 |
| ISSN: | 0169-4332 |
| DOI: | 10.1016/j.apsusc.2007.02.074 |
| Popis: | Laser-assisted growth of microstructures on spatially confined substrates is experimentally studied. The experiments are performed using a copper-vapor laser with pulse duration of 20 ns, and repetition rate of 7.5 kHz. Ropes made of Ni–Cr wires with diameter of 50–100 μm, as well as the edge of 50 μm thick Ni foils were exposed to multiple laser pulses. The morphology of structures that grow on these targets drastically differs from periodic array of micro-cones observed on semi-infinite targets made of the same materials. In case of wires the structures have radial symmetry and do not show any periodicity, while in case of a foil the periodic structures are aligned along its edges. The model of micro-structures formation in spatially confined conditions is elaborated based on the numerical solution of the heat conduction and hydrodynamics equations. It is shown that boundary conditions imposed by confined target onto melt flow strongly affect the structure morphology. The micro-structure formation is related to the confinement of melt flow under combined action of both capillary forces and gradients of surface tension. |
| Databáze: | OpenAIRE |
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