Effect of Structure and Surface Roughness on Wetting Angle of a Hypoeutectic Cast Iron

Authors

Department of Materials Engineering, Isfahan University of Technology, Isfahan, Iran

Abstract

Preliminary results of a research on the effects of microstructure and surface roughness of a hypoeutectic cast iron on its wetting angle are presented in this article. For this purpose, molten cast iron was solidified at different cooling rates to produce two samples of the same composition, i.e. a gray cast iron with A type flake graphite and a white cast iron. Two samples were then prepared in polished, electroetched (four different stages) and mechanically abraded (four different stages) conditions and their wetting angles were measured after evaluating their roughness profile. Maximum and minimum wetting angles were observed on white cast iron surfaces roughened with 80 and 800 sand papers which were equal to 42 and 13 degrees, respectively.Wetting angles of electroetched white cast iron surfaces varied between 25 and 31 degrees by varying surface roughness. Maximum and minimum wetting angles on the surface of gray cast iron were obtained in stage one (40 degree) and stage three (25 degree) of electroetching, respectively. Wetting angles on mechanically abraded surfaces of this sample varied between 27 and 31 degrees. Then, the surface roughness factor and the solid fraction in contact with water were calculated using Wenzel equation and Cassie Baxter equation, respectively, and Wenzel and Cassie-Baxter wetting angles of the surfaces were calculated and were compared with their corresponding measured wetting angles. The results indicated that the surface microstructure and the type of constituents present at the surface, surface-roughening method and surface-roughness value influence the cast iron surface wettability, and it is possible to modify metal wetting angle by modification of its structure, surface-roughness method and surface-roughness value. It was also shown that in gray cast iron, the wetting behavior of the electroetched surfaces followed Cassie-Baxter equation in the first and second stages of electroetching and followed Wenzel equation at higher surface roughness (third and fourth stages of electroetching). In all stages of mechanically abrading, the surface of this sample followed Wenzel equation. The wetting behavior of the white cast iron followed Wenzel equation in all electroetching stages. In mechanically abraded conditions, the white cast iron wettability was variable and depended on the surface roughness.

Keywords


1. Feng, L., Li, S., Li, Y., Li, H., Zhang, L. and Zhai, J., “Super-Hydrophobic Surfaces, from Natural to Artificial”, Advanced Materials, Vol. 14, pp. 1857-1860, 2002.
2. Celia, E., Darmanin, T., Givenchy, E., Amigoni, S. and Guittard, F., “Recent Advances in Designing Super-Hydrophobic Surfaces”, Colloid and Interface Science, Vol. 402, pp. 1–18, 2013.
3. Peng, C.W., Chang, K.C., Weng, C.G, Lai, M.C. , Hsu, C.H., Hsu, S.C. and Hsu, Y.Y., “Nano-Casting Technique to Prepare Polyaniline Surface with Biomimetic Super-Hydrophobic Structures for Anticorrosion Application”, Electrochimica Acta, Vol. 95, pp. 192-199, 2012.
4. Gupta, A., Sasikala., S., Mahadik, D.B., Rao, A.V. and Barshilia H.C., “Dual-Scale Rough Multifunctional Super-Hydrophobic ITO Coatings Prepared by Air Annealing of Sputtered Indium–Tin Alloy Thin Films”, Applied Surface Science,
Vol. 258, pp. 9723-9731, 2012.
5. Wang, Z., Li, Q., She, Z., Chen, F., Li, F., Zhang, X. and Zhang, P., “Facile and Fast Fabrication of Super-Hydrophobic Surface on Magnesium Alloy”, Applied Surface Science, Vol. 271, pp. 182-192, 2013.
6. Shi, X., Lu, S. and Xu, W., “Fabrication of CuZn5-ZnO-CuO Micro-Nano Binary Super-Hydrophobic Surfaces of Cassie-Baxter and Gecko Model on Zinc Substrates”, Materials Chemistry and Physics,
Vol. 134, pp. 657-663, 2013.
7. Ma, M. and Hill, R.M., “Super-Hydrophobic Surfaces”, Current Opinion in Colloid & Interface Science, Vol.11, pp. 193–202, 2006.
8. Xie, D. and Li, W., “A Novel Simple Approach to Preparation of Super-Hydrophobic Surfaces of Aluminum Alloys”, Applied Surface Science,
Vol. 258, pp. 1004–1007, 2011.
9. Min, T., “Design and Fabrication of Super-Hydrophobic Surfaces by Laser Micro/Nano Processing”, Ph.D. Thesis, National University of Singapore, 2012.
10. Wua, B., Zhou, M., Li, J., Ye, X., Li, G. and Cai, L., “Superhydrophobic Surfaces Fabricated by Microstructuring of Stainless Steel using a Femtosecond Laser”, Applied surface science,
Vol. 256, pp. 61–66, 2009.
11. Yan, Y., Ga, N. and Barthlott, W., “Mimicking Natural Super-Hydrophobic Surfaces and Grasping the Wetting Process: A Review on Recent Progress in Preparing Super-Hydrophobic Surfaces”, Advances in Colloid and Interface Science, Vol. 169, pp. 80-105, 2013.
12. Ning, T., Xu, W. and Lu, S., “One-Step Controllable Fabrication of Super-Hydrophobic Surfaces with Special Composite Structure on Zinc Substrates”, Colloid and Interface Science, Vol. 361, pp. 388-396, 2011.
13. Roach, P., Shirtcliffe, N.J. and Newton, M.I., “Progress in Super-Hydrophobic Surface Development”, Soft Matter, Vol. 4, pp. 224–240, 2008.
14. Manoudis, P.N., Karapanagiotis, I., Tsakalof,
A., Zuburtikudis, I. and Panayiotou, C., “Superhydrophobic Composite Films Produced on Various Substrates”, Langmuir, Vol.24, pp. 11225-11232, 2008.
15. Guo, Z.G., Zhou, F., Hao, J.C. and Liu, W.M., “Stable Biomimetic Super-Hydrophobic Engineering Materials”, American Chemical Society, Vol. 127,
pp. 15670–15671, 2005.
16. Wang, Q., Zhang, B.W., Qu, M.N., Zhang, J.Y. and He, D.I., “Fabrication of Superhydrophobic Surfaces on Engineering Material Surfaces with Stearic Acid”, Applied Surface Science, Vol.254, pp. 2009–2012, 2008.
17. Jafari, R., Menini, R. and Farzaneh, M., “Super-Hydrophobic and Ice-Phobic Surfaces Prepared by RF-Sputtered Polytetrafluoroethylene Coatings”, Applied Surface Science, Vol. 257, pp. 1540-1543, 2010.
18. Hejazi, V., Dorri, A., Rohatgi, P. and Nosonovsky, P.M., “Beyond Wenzel and Cassie−Baxter: Second-Order Effects on the Wetting of Rough Surfaces”, Langmuir, Vol. 30, pp. 9423-9429, 2014.
19. Tabrizi, S., “Effect of Mechanical Abrasion on Oil/Water Contact Angle in Metals”, M.S Thesis, University of Wisconsin, Milwaukee, 2012.
20. Lua, B. and Lib, N.“Versatile Aluminum Alloy Surface with Various Wettability”, Applied Surface Science, Vol. 326, pp. 168-173, 2015.
21. Kam, D., Bhattacharya, S. and Mazumder, J., “Control of the Wetting Properties of an AISI 316L Stainless Steel Surface by Femto-second Laser-Induced Surface Modification”, Journal of Micromechanics and Microengineering, Vol. 22,
pp. 6-13, 2012.
22. Bo, W., Ming, Z. and Jian, L., “Superhydrophobic Surfaces Fabricated by Microstructuring of Stainless Steel using a Femto second Laser”, Applied Surface Science, Vol. 256, pp. 61-66, 2009.

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