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Preparation and characterization of TiO2/acrylic resin composite coatings on sintered NdFeB permanent magnets by electrochemical deposition

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Abstract

The sintered NdFeB permanent magnets are widely used in various industries because of their excellent magnetic and comprehensive properties. However, they are seriously hindered to further developments and applications owing to its poor corrosion resistance. In this paper, TiO2/acrylic resin composite coatings were successfully prepared on the sintered NdFeB permanent magnets by electrochemical deposition for the first time, and the corrosion behaviors were investigated by using immersion testing and potentiodynamic polarization tests. It is found that the coating is a composite, being composed of polymerized acrylic resin as the matrix and nano-rutile TiO2 particles (−200 nm) as the reinforcements. It is about 25 μm in thickness and its surface and cross-section exhibit uniform and smooth with no pores, cracks, and other defects. Compared with those of the uncoated NdFeB magnets, the weight loss of the coated samples immersed in H2SO4 solution reduces by two orders of magnitude, corrosion current density decreases by four orders of magnitude, and the corrosion potential of the coated sample is shifted in the noble direction by 400 mV. The mechanisms of corrosive resistance enhancement were discussed.

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Acknowledgments

This study was financially supported by the National Science and Technology Key Support Projects of China (No. 2012BAE02B01), the Major Science and Technology Special Projects of Jiangxi Province (No. 2010AZX00200), the Science and Technology Plan Projects of Jiangxi Province (Industrial field) (No. 20121BBE50001), and the Science and Technology Plan Projects of Department of Education of Jiangxi Province (No. KJ201109132281).

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  1. School of Materials Science and Engineering, Nanchang Hangkong University, Nanchang, 330063, China

    Zhen-Chen Zhong, Ji-Lin Xu, Zheng-Xian Huang & Jun-Ming Luo

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  1. Zhen-Chen Zhong
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  2. Ji-Lin Xu
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Correspondence to Zhen-Chen Zhong.

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Zhong, ZC., Xu, JL., Huang, ZX. et al. Preparation and characterization of TiO2/acrylic resin composite coatings on sintered NdFeB permanent magnets by electrochemical deposition. Rare Met. 33, 703–708 (2014). https://doi.org/10.1007/s12598-013-0142-x

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  • DOI: https://doi.org/10.1007/s12598-013-0142-x

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