海洋环境下磁场对电磁屏蔽涂层保护性能的影响
发布时间：2018-11-25 09:02
【摘要】：采用电化学阻抗谱(EIS)研究了3.5%(质量分数)NaCl溶液中外加磁场对Ni基电磁屏蔽涂层单、双层体系保护性能的影响,并采用体视显微镜与扫描电子显微镜对浸泡后涂层的表面及截面形貌特征进行了观察。结果表明,单层Ni基涂层体系下,磁场的作用表现为阻滞了溶液的扩散,使得其低频阻抗模值|Z|0.01Hz随浸泡时间的增加下降速度减缓,这是由于磁场使涂层中Ni颗粒重新排布,减少了涂层内缺陷;对于电磁屏蔽涂层/丙烯酸聚氨酯清漆双层体系,EIS结果表明外加磁场使涂层|Z|0.01Hz下降更快,而磁场方向对|Z|0.01Hz的变化规律无明显影响。这说明尽管磁场优化了底漆中Ni颗粒在涂层中的分布,提高了电磁屏蔽底漆的保护性,但是对于丙烯酸聚氨酯面漆的失效过程,磁场对电解质扩散的加速作用占主导地位,二者叠加总体来说磁场加速了双层涂层体系腐蚀过程。
[Abstract]:The effect of external magnetic field in 3.5% (mass fraction) NaCl solution on the protective properties of single and double layers of electromagnetic shielding coating based on Ni was investigated by electrochemical impedance spectroscopy (EIS). The surface and cross section morphologies of the coating were observed by stereoscopic microscope and scanning electron microscope. The results show that the effect of magnetic field on the monolayer Ni coating system is to block the diffusion of the solution and slow down the decrease rate of the low frequency impedance modulus Z 0.01Hz with the increase of soaking time, which is due to the rearrangement of Ni particles in the coating by magnetic field. The defects in the coating are reduced; For the electromagnetic shielding coating / acrylic polyurethane varnish bilayer system, the EIS results show that the applied magnetic field decreases the 0.01Hz of the coating faster, but the direction of the magnetic field has no obvious effect on the variation of Z 0.01Hz. This shows that although the magnetic field optimizes the distribution of Ni particles in the primer and improves the protection of the electromagnetic shielding primer, the acceleration of electrolyte diffusion by magnetic field plays a dominant role in the failure process of acrylic polyurethane topcoat. On the whole, the magnetic field accelerates the corrosion process of the double layer coating system.
【作者单位】： 北京科技大学腐蚀与防护中心;
【基金】：国家重点基础研究发展计划(973计划)资助项目(2014CB643300) 国家自然科学基金重点资助项目(51133009,u1560104)
【分类号】：TG174.4
，
本文编号：2355542
[Abstract]:The effect of external magnetic field in 3.5% (mass fraction) NaCl solution on the protective properties of single and double layers of electromagnetic shielding coating based on Ni was investigated by electrochemical impedance spectroscopy (EIS). The surface and cross section morphologies of the coating were observed by stereoscopic microscope and scanning electron microscope. The results show that the effect of magnetic field on the monolayer Ni coating system is to block the diffusion of the solution and slow down the decrease rate of the low frequency impedance modulus Z 0.01Hz with the increase of soaking time, which is due to the rearrangement of Ni particles in the coating by magnetic field. The defects in the coating are reduced; For the electromagnetic shielding coating / acrylic polyurethane varnish bilayer system, the EIS results show that the applied magnetic field decreases the 0.01Hz of the coating faster, but the direction of the magnetic field has no obvious effect on the variation of Z 0.01Hz. This shows that although the magnetic field optimizes the distribution of Ni particles in the primer and improves the protection of the electromagnetic shielding primer, the acceleration of electrolyte diffusion by magnetic field plays a dominant role in the failure process of acrylic polyurethane topcoat. On the whole, the magnetic field accelerates the corrosion process of the double layer coating system.
【作者单位】： 北京科技大学腐蚀与防护中心;
【基金】：国家重点基础研究发展计划(973计划)资助项目(2014CB643300) 国家自然科学基金重点资助项目(51133009,u1560104)
【分类号】：TG174.4
，
本文编号：2355542
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