Experimental Research On Fabrication Of Superhydrophobic Or Superoleophobic Surfaces On SiC/Al Composites

Because of its favorable properties including self-cleaning,high corrosion resistance,low friction coefficient,anti-drag and anti-adhesion,superhydrophobic/superoleophobic surface has been considered to have a good application prospect,and thus its preparation has attracted attentions of many researchers home and abroad.The metal matrix superhydrophobic or superoleophobic surface obtained up to now cannot have desired work lifetime and reliability properties.Therefore,this paper utilized etching method to prepare superhydrophobic or superoleophobic surface based on silicon carbide particulate reinforced aluminum matrix(SiC/Al)composite,which aim at gaining self-cleaning surfaces with higher weather resistance,longer work lifetime and better reliability.With SiC/Al composite serving as substrate,this study analyzed emphatically the microstructure characteristics and wetting characteristics of the prepared surface,evaluated the superhydrophobic or superoleophobic properties of the prepared surface,and measured its temperature shock resistance.The details are as follows:(1)The surface morphology,wetting properties of the SiC/Al composites etched with a Beck’s dislocation etchant have been studied,and its temperature shock resistance have been analyzed in this study.Results indicate that: A prefect hierarchical structure consisting of particle-shaped microstructures and nano-sized pit structures is formed on the etched SiC/Al composite after etching for 5s;After modified by fluorosilane coating,the etched SiC/Al composite surfaces show excellent superhydrophobicity with a water contact angle of up to 165.7o and a small slide angle of as low as 3o.(2)The surface morphology,wetting properties of the SiC/Al composites fabricated using electrochemical etching process have been studied,and its temperature shock resistance have been analyzed in this study.Results indicate that: A special hierarchical structure consisting of particle-shaped microstructures and nanostructrues(particle-or squama-shaped)is formed on the etched SiC/Al composite at the current density of 6 A/dm2;Superhydrophobic surface can be obtained on SiC/Al composite,achieving a water contact angle of up to 160.7o and an extremely small tilting angle of 5o.(3)The surface morphology,wetting properties of the SiC/Al composites processed by the electrochemical etching and followed boiling water treating have been studied,and its temperature shock resistance have been analyzed in this study.Results indicate that: The composite surface processed by the electrochemical etching and followed boiling water treating is full of nanoscale linear structures,and these nanoscale structures covered become more intensively distributed with the extension of the processing time with boiling water;Under optimized process conditions,superoleophobic surface can be obtained,achieving a water contact angle of up to 161.2o,an oil contact angle of up to 155o,a small water sliding angle of 2o and a small oil sliding angle of 20o.Compared with pure Al,the superhydrophobic and superoleophobic surfaces can be easier formed on the SiC composite,and they all have a better property of temperature shock resistance.This method has a wide application prospect.