The influence of the surface microtexture on wettability properties and drop evaporation

• Published in: Surface & coatings technology Vol. 375; pp. 458 - 467
• Main Authors: Misyura, S.Y., Kuznetsov, G.V., Feoktistov, D.V., Volkov, R.S., Morozov, V.S., Orlova, E.G.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 15-10-2019; Elsevier BV
• Subjects: Aluminum base alloys; Chemical analysis; Drop evaporation; Electron microscope; Evaporation; Evaporation rate; Free convection; Laser beam heating; Microtexture; Microtexture surface; Optimization; Organic chemistry; Particle image velocimetry; Surface laser exposure; Surface treatment; Thermocapillary force; Velocity distribution; Water drops; Wettability; Electron microscope; Surface laser exposure; Microtexture surface; Drop evaporation
• ISSN: 0257-8972; 1879-3347
• DOI: 10.1016/j.surfcoat.2019.07.058

The influence of different microstructure of the surface of aluminum alloy on the free convection in the liquid and the evaporation of the water drop were studied experimentally. Various textures were created using laser surface treatment. The character of water drop evaporation on heated structured surfaces was compared with that on untreated rough surface. Velocity fields were measured using the Micro Particle Image Velocimetry (Micro PIV) method. A chemical analysis of sample surfaces in the cavity and in its vicinity was carried out. The effect of different textures on the wettability properties is shown. The evaporation rate of a drop depends on several competing factors: the diameter of the wetted drop spot, the drop height, the convection due to the surface thermocapillary forces, and the convection caused by the surface microstructures. The article also assesses the individual impact of these factors. The greatest intensification of convection and evaporation is associated with textures in the form of craters with a diameter of about 50–100 μm. The competing influence of several parameters leads to the need of their optimization. This paper demonstrates a general approach to such an optimization.
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•The influence of surface microstructure on wettability, convection and evaporation of water drops has been investigated.•Various textures have been created using laser surface treatment.•Cavities of 50–100 μm demonstrate the highest convection and drop evaporation rate.•The competing influence of several parameters leads to the need of their optimization.