Silane coupling agent KH560 was used to modify the surface of nano-α-Al2O3 in ethanol-aqueous solution with different proportions. The particle size of nano-α-Al2O3 was determined by nano-particle size analyzer, and the effects of nano-α-Al2O3 content, ethanol-aqueous solution ratio and KH560 dosage on the dispersion and particle size of nano-α-Al2O3 were investigated. The material structure before and after modification was determined by Fourier transform infrared spectroscopy (FTIR). Aqueous polyurethane resin and inorganic components are combined with modified nano-α-Al2O3 dispersion to form chromium-free passivation solution. The solution is coated on the galvanized sheet, the adhesion and surface hardness are tested, the bonding strength of the coating and the surface hardness of the substrate are discussed. The corrosion resistance and surface morphology of the matrix were investigated by electrochemical test, neutral salt spray test and scanning electron microscope test. The chromium-free passivation film formed after the modification of nano-α-Al2O3 increases the surface hardness of galvanized sheet by about 85%. The corrosion resistance of the film is better than that of a single polyurethane film. The results show that the surface hardness and corrosion resistance of polyurethane resin composite passivation film are significantly improved by the introduction of nano-α-Al2O3.
References
[1]
Fu, Q.L., Wu, A.R., Du, W.H., et al. (2020) Application Status and Prospect of Surface Strengthening Technology for Metal Materials. Journal of Hunan Institute of Engineering, 30, 52-56.
[2]
Wu, H.J., Chen, J.H. and Lu, J.T. (2004) Research Progress on Corrosion Resistance Mechanism of Zinc Plating Without Chromium Passivation. Material Protection, 37, 43-45.
[3]
Wang, L. (2012) Preparation, Properties and Film-Forming Mechanism of Silane Composite Passivation Film on Galvanized Sheet Surface. Ph.D. Thesis, Thesis, Northeastern University, Shenyang.
[4]
Zhao, X.F., Yang, R.F., Miao, Y.F., et al. (2014) Study on Microstructure and Electrochemical Properties of Zn-Zr Composite Nanofilms on Hot Galvanized Sheet Surface. Corrosion Science and Protection Technology, 26, 459-463.
[5]
Nie, D.W. (2019) Preparation and Properties of Hydrophilic Resin on Galvanized Sheet Surface. Ph.D. Thesis, Dalian Polytechnic University, Dalian.
[6]
Wu, H.B., Xu, B. and Tan, Z.Q. (2019) Research Progress of Chromium-Free Passivation Process for Metal Surface. Guangzhou Chemical Industry, 47, 31-32, 79.
[7]
Fedel, M., Druart, M.E., Olivier, M., et al. (2010) Compatibility between Cataphoretic Electro-Coating and Silane Surface Layer for the Corrosion Protection of Galvanized Steel. Progress in Organic Coatings, 69, 118-125. https://doi.org/10.1016/j.porgcoat.2010.04.003
[8]
Hou, K.W., Li, Y.X., Zhou, J.P., et al. (2020) Preparation and Coating Properties of Cationic Photocurable Waterborne Polyurethane. Journal of Nanchang Hangkong University (Natural Science Edition), 34, 23-29.
[9]
Somisetti, V., Narayan, R. and Kothapalli, R.V.S.N. (2019) Multifunctional Polyurethane Coatings Derived from Phosphate Cardanol and Undecylenic Acid Based Polyols. Progress in Organic Coatings, 134, 91-102. https://doi.org/10.1016/j.porgcoat.2019.04.077
[10]
Hou, X.Y., Huang, H.B., Li, Y.F., et al. (2022) Stability and Variability—α-Alumina: From Properties, Synthesis and Application. China Ceramic Industry, 29, 30-38.
[11]
Wang, L.P., Guo, Z.H., Chi, J.Z., et al. (2015) Research Progress of Multi-Purpose Development of Alumina. Inorganic Salt Industry, 47, 11-15, 62.
[12]
Fu, L., Huang, A., Gu, H., et al. (2018) Properties and Microstructures of Lightweight Alumina Containing Different Types of Nano-Alumina. Ceramics International, 44, 17885-17894.
[13]
Liu, L.Z., Gao, L., Song, Y.X., et al. (2008) Effect of Coupling Agent on Structure and Properties of Polyimide/Nano-Al2O3 Hybrid Films. Journal of Functional Materials, 39, 1887-1889.
[14]
Wang, Y., Zhu, S.G. and Dong, W.W. (2015) Preparation of Nano-Sized Flake Alumina by Hydrothermal Method. Journal of Materials Science and Engineering, 33, 401-404.
[15]
Sun, J.H., Yi, J.F., Qing, P.L., et al. (2021) Preparation of Ultrafine Spherical Alumina Powder by Hydrothermal Method. China Ceramics, 57, 30-35.
[16]
Ghanizadeh, S., Bao, X., Vaidhyanathan, B., et al. (2014) Synthesis of Nano α-Alumina Powders Using Hydrothermal and Precipitation Routes: A Comparative Study. Ceramics International, 40, 1311-1319. https://doi.org/10.1016/j.ceramint.2013.07.011
[17]
Shin, D.C., Park, S.S., Kim, J.H., et al. (2014) Study on α-Alumina Precursors Prepared Using Different Ammonium Salt Precipitants. Journal of Industrial & Engineering Chemistry, 20, 1269-1275. https://doi.org/10.1016/j.jiec.2013.07.003
[18]
Liao, H., Liao, Q.L. and Wang, F. (2010) Hydrothermal Synthesis of α-Alumina Hollow Microspheres. China Powder Technology, 16, 14-17.
[19]
Shan, F.R., Yu, Z.M., Luo, L.S., et al. (2013) Study on the Surface Modification of Nano-Al2O3 with Silane Coupling Agent KH550. New Chemical Materials, 41, 169-170, 185.
[20]
Yao, H.W., Chen, W., Mei, W.T., et al. (2023) Effect of Silane Coupling Agent on Aluminum Hydroxide Crushing and Surface Modification. Light Metals, No. 8,8-13.
[21]
Liu, H.Y., Li, D.L. and Li, X. (2011) Silane Coupling Agent KH-560 Modified Nano-Silica. Chemical World, 52, 456-458, 462.
[22]
Wang, H.P., Gui, P.C. and Hu, S.Q. (2020) Comprehensive Experiment on Hydrophobic Modification of Nano-Alumina by Silane Coupling Agent. Experimental Technology and Management, 37, 154-157.
[23]
Hao, J. (2023) Study on the Application of Silane Coupling Agent in Nanomaterial Modified Waterborne Polyurethane. Shanxi Chemical Industry, 43, 29-31.
[24]
Cao, J., Zhang, Y.X., Wang, X.Z., et al. (2016) Exploration of the Conditions for the Modification of Nano-Alumina by Silane Coupling Agent. New Chemical Materials, 44, 207-209.
[25]
Chen, J.H. and Zhu, C.L. (2011) Study on the Modification of Nano-Al2O3 with Silane Coupling Agent. Guangdong Chemical Industry, 38, 253-255, 246.
[26]
Wang, B., Liu, W., Zhu, Y., et al. (2007) A General Procedure for Surface Modification of Nano-Alumina and Its Application to Dendrimers. Journal of Wuhan University of Technology-Mater. Sci. Ed., 22, 453-456. https://doi.org/10.1007/s11595-006-3453-z
[27]
Zhao, C.F., Yi, Z.Y. and Li, B. (2007) Effect of Microstructure of α-Type Alumina on Infrared Spectra. Spectrum Laboratory, No. 3, 341-344.
[28]
Wu, Z.J. (2022) Gravimetric Determination of Chromium-Free Passivation Film Quality of Galvanized Steel Plate. Chinese Society of Metals. Proceedings of the 13th China Iron and Steel Annual Meeting—Surface and Coating. Inspection and Testing Center of Ben Steel Sheet, Chongqing, 23 November 2022, 104-107.
[29]
Fan, Z.G. (2011) Determination of Coating Quality of Galvanized Steel Plate by X-Ray Fluorescence Spectrometry. Physicochemical Inspection (Chemistry Branch), 47, 511-513, 516.
[30]
Jiao, Z.H., Feng, Q.Y., Fan, Z.Y., et al. (2022) Application of Chromium-Free Passivation Film Thickness Measurement by X-Ray Fluorescence Spectrometry in Galvanizing Units. Henan Metallurgy, 30, 40-43.
[31]
Dong, N.N., He, D.J., Liu, W.H., et al. (2023) Corrosion Resistance of Chromium-Free Passivated Galvanized Sheet after Forming. Electroplating and Finishing, 42, 56-62.
[32]
Xi, P., Yao, Y.H. and Wang, W.F. (2022) Study on Chromium-Free Passivation of Galvanized Sheet Composite and Its Properties. New Materials for High Speed Railway, 1, 36-40.
[33]
Kang, Y.F. (2020) Study on Corrosion Resistance of Chromium-Free Passivation Film of Hot-Dip Galvanized Steel Sheet. Shandong Metallurgy, 42, 37-39.
[34]
Zheng, X.R., Liu, C., Yu, X.H., et al. (2018) Microstructure and Corrosion Resistance of Chromium-Free Composite Passivation Films. Surface Technology, 47, 197-203.
