【摘要】：采用電化學阻抗譜(EIS)研究了3.5%(質量分數(shù))NaCl溶液中外加磁場對Ni基電磁屏蔽涂層單、雙層體系保護性能的影響,并采用體視顯微鏡與掃描電子顯微鏡對浸泡后涂層的表面及截面形貌特征進行了觀察。結果表明,單層Ni基涂層體系下,磁場的作用表現(xiàn)為阻滯了溶液的擴散,使得其低頻阻抗模值|Z|0.01Hz隨浸泡時間的增加下降速度減緩,這是由于磁場使涂層中Ni顆粒重新排布,減少了涂層內缺陷;對于電磁屏蔽涂層/丙烯酸聚氨酯清漆雙層體系,EIS結果表明外加磁場使涂層|Z|0.01Hz下降更快,而磁場方向對|Z|0.01Hz的變化規(guī)律無明顯影響。這說明盡管磁場優(yōu)化了底漆中Ni顆粒在涂層中的分布,提高了電磁屏蔽底漆的保護性,但是對于丙烯酸聚氨酯面漆的失效過程,磁場對電解質擴散的加速作用占主導地位,二者疊加總體來說磁場加速了雙層涂層體系腐蝕過程。
[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.
【作者單位】： 北京科技大學腐蝕與防護中心;
【基金】：國家重點基礎研究發(fā)展計劃(973計劃)資助項目(2014CB643300) 國家自然科學基金重點資助項目(51133009,u1560104)
【分類號】：TG174.4
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本文編號：2355542