Fabrication of hierarchical micro/nano structure surface on copper by EDM and its hydrophobicity
HE Zhao-rong1,2, JIE Xiao-hua1, LIAN Wei-qi1
1. School of Materials and Energy, Guangdong University of Technology, Guangzhou 510036, China;
2. College of Mechanical and Electrical Engineering, Guangdong University of Petrochemical Technology, Maoming 525000, Guangdong, China
Abstract：The hierarchical micro-nano structure surface on copper was fabricated by electrical discharge machining (EDM). The hydrophobic property was increased due to the hierarchical micro/nano structure (HMNS), which consisted of the micro/nano scale holes, molten balls, recast regions and the micro thermal cracks. The effects of the pulse width on the hydrophobicity of HMNS were investigated. The results indicate that with the increase of the pulse width, the quantity of the micro-nano scale holes increases. The distribution of other hierarchical micro structures is more homogeneous. The effective area of "air cushion" increases, which can trap more air in the HMNS. And the hydrophobicity of HMNS also increases. The proportion of the solid-liquid interface area (fsl) reduces. The contact area between the water droplet and "air cushion" in the HMNS increases. Therefore, the effect of the physical adsorption for the HMNS on the water droplet is weakened. The contact angles of the HMNSs can be increased up to (144.7±2.1)°, and the range of contact angle hysteresis is (8.46±3.3)°-(14.10±1.2)°.
何照荣, 揭晓华, 连玮琦. 电火花加工制备铜基微纳层次结构及其疏水性能[J]. 材料工程, 2020, 48(1): 144-149.
HE Zhao-rong, JIE Xiao-hua, LIAN Wei-qi. Fabrication of hierarchical micro/nano structure surface on copper by EDM and its hydrophobicity. Journal of Materials Engineering, 2020, 48(1): 144-149.
[1] SELIM M S,SHENASHEN M A,HASEGAWA S I,et al.Synthesis of ultrahydrophobic and thermally stable inorganic-organic nanocomposites for self-cleaning foul release coatings[J].Chemical Engineering Journal,2017,320(15):653-666.
[2] BHARATHIDASAN T,KUMAR S V,BOBJI M S,et al.Effect of wettability and surface roughness on ice-adhesion strength of hydrophilic,hydrophobic and superhydrophobic surfaces[J].Applied Surface Science,2014,314(31):241-250.
[3] QIAN H,XU D,DU C,et al.Dual-action smart coating with a self-healing super-hydrophobic surface and anti-corrosion properties[J].Journal of Materials Chemistry A,2017(5):2355-2364.
[4] YAN Y L,CUI M Y,JIANG W D,et al.Drag reduction in reservoir rock surface:hydrophobic modification by SiO2 nanofluids[J].Applied Surface Science,2017,396:1556-1561.
[5] LATTHE S S,GURAV A B,MARUTI C S,et al.Recent progress in preparation of superhydrophobic surfaces:a review[J].Journal of Surface Engineered Materials and Advanced Technology,2012,2:76-94.
[6] BAE W G,SONG K Y,RAHMAWAN Y,et al.One-step process for superhydrophobic metallic surfaces by wire electrical discharge machining[J].ACS Applied Materials & Interfaces,2012,4(7):3685-3691.
[7] WEISENSEE P B,TORREALBA E J,RALEIGH M,et al.Hydrophobic and oleophobic re-entrant steel microstructures fabricated using micro electrical discharge machining[J].Journal of Micromechanics & Microengineering,2014,24(9):095020.
[8] YU H,LIAN Z,WAN Y,et al.Fabrication of durable superamphiphobic aluminum alloy surfaces with anisotropic sliding by HS-WEDM and solution immersion processes[J].Surface & Coatings Technology,2015,275:112-119.
[9] LIAN Z,XU J,WANG Z,et al.Research on HS-WEDM and chemical etching technology of superamphiphobic surfaces on Al substrates[J]. Micro & Nano Letters,2016,11(8):425-429.
[10] LIAN Z,XU J,WANG Z,et al.Reversibly switchable wettability between underwater superoleophobicity and oleophobicity of titanium surface via ethanol immersion and dark storage[J].Applied Surface Science,2016,390:244-247.
[11] XU J,XIA K,LIAN Z,et al.Surface properties on magnesium alloy and corrosion behaviour based high-speed wire electrical discharge machine power tubes[J].Micro & Nano Letters,2016,11(1):15-19.
[12] HOCKENBERRY T O,WILLIAMS E M.Dynamic evolution of events accompanying the low-voltage discharges employed in EDM[J].IEEE Transactions on Industry & General App-lications,1984,3(4):302-309.
[13] PARK J W,SONG K Y,CHUNG D K,et al.Fabrication of micro-lenticular patterns using WEDM-grooving and electrolytic polishing[J].Journal of Micromechanics & Microengineering,2013,23(12):5034-5040.
[14] 常伟杰,陈远龙,张建华,等.电火花加工单脉冲放电通道直径扩展规律研究[J].机械工程学报,2016,52(9):208-212. CHANG W J,CHEN Y L,ZHANG J H,et al.Single pulse discharge channel expansion laws of EDM[J].Journal of Mechanical Engineering,2016,52(9):208-212.
[15] CASSIE A B D.Wettability of porous surfaces[J].Trans Faraday Soc,1944,40(1):546-551.
[16] LEE K,LYU S,LEE S,et al.Characteristics and self-cleaning effect of the transparent super-hydrophobic film having nanofibers array structures[J].Applied Surface Science,2010,256(22):6729-6735.
[17] WANG J Y,BETELU S,LAW B M.Line tension effects near first-order wetting transitions[J].Physical Review Letters,1999,83(18):3677-3680.
[18] 马学虎,张宇.线张力对接触角影响的理论分析[J].应用基础与工程科学学报,2004,12(3):268-272. MA X H,ZHANG Y.Analysis of the effect of line tension on contact angle[J].Journal of Basic Science and Engineering,2004,12(3):268-272.
2020, Vol. 48 
