基于皮秒激光7075 Al合金超疏水表面的制备及其工艺优化

Preparation and process optimization of superhydrophobic surface on 7075 Al alloy based on picosecond laser

为在Al合金表面获得稳定的超疏水性能,进一步拓宽Al合金材料在工业领域的应用范围,研究了一种简单、灵活、可靠的超疏水表面制备方法。首先,基于超疏水表面结构特征,采用单因素控制变量法和响应面法对激光加工参数进行了选取和优化。后采用皮秒激光刻蚀和硬脂酸处理相结合的方式获得了(超)疏水表面。通过控制激光扫描间距间接操控表面形貌的方式研究了微纳结构对表面润湿性的影响。利用接触角测量仪、SEM、共聚焦显微镜、FTIR等分析了样品的表面润湿性、形貌及化学成分。结果表明:最佳激光刻蚀参数为:扫描次数2次,扫描速度460 mm/s,频率835 kHz,平均功率21 W;扫描间距为20~80μm的表面具有超疏水性,扫描间距为100~160μm的表面具有疏水性。当扫描间距为20、80μm时,接触角最大为154°,且表面黏附性很低。本文对在金属表面快速获得稳定超疏水性具有指导意义。

In order to obtain stable superhydrophobic properties on Al alloy surface and further expand the industrial application of Al alloy material,a simple,flexible and reliable preparation method of superhydrophobic surface was studied.Firstly,based on the structural characteristics of superhydrophobic surface,single factor control variable method and response surface method were used to select and optimize the laser machining parameters.The(super)hydrophobic surface was obtained by picosecond laser etching and stearic acid treatment.The influence of micro-nano structure on surface wettability was studied by controlling laser scanning distance to indirectly control surface topography.The surface wettability,morphology and chemical composition of the samples were analyzed by contact angle measuring instrument,SEM,confocal microscope and FTIR.The results show that the optimal laser etching parameters are as follows:Number of scanning is 2 times,scanning speed is 460 mm/s,frequency is 835 kHz,average power is 21 W;The surface with scanning interval of 20-80μm exists superhydrophobicity,and the surface with scanning interval of 100-160μm exists hydrophobicity.The maximum contact angle is 154°when the scanning interval is 20μm and 80μm,and the surface has low adhesion.This paper has guiding significance for obtaining stable superhydrophobicity on metal surface quickly.