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研究了热处理后TiN涂层在模拟海水中的腐蚀行为,采用电化学阻抗谱(EIS)、动电位极化曲线、扫描电镜和能谱分析等技术研究了热处理后TiN涂层电化学腐蚀参数及组织的变化。结果表明:热处理后TiN涂层的耐蚀性明显提高,自腐蚀电流仅为热处理前的13.3%,极化电阻约是热处理前的20倍;电化学阻抗谱描绘了热处理后涂层的腐蚀过程及导致涂层腐蚀的主要因素,涂层局部的孔隙腐蚀是引起电化学腐蚀参数变化的主要因素,腐蚀初期孔隙电阻由大变小,后期又会由小变大,从而使涂层的腐蚀速率发生变化;热处理会使涂层的通孔率降低为87%,主要原因是在热处理过程,TiN与大气中的O2发生了氧化反应,生成密度较TiN小的TiO2相和Ti3O相,使涂层中的部分通孔被封闭,耐蚀性得以提高。
The corrosion behavior of TiN coating in simulated seawater after heat treatment was studied. The electrochemical corrosion parameters of TiN coating after heat treatment were studied by electrochemical impedance spectroscopy (EIS), potentiodynamic polarization curve, scanning electron microscopy and energy spectrum analysis. Organizational changes. The results show that the corrosion resistance of TiN coating increases obviously after heat treatment, the self-corrosion current is only 13.3% before heat treatment and the polarization resistance is about 20 times that before heat treatment. The electrochemical impedance spectroscopy depicts the corrosion process of the coating after heat treatment And the main factor leading to the corrosion of the coating. The local corrosion of the coating is the main factor that causes the variation of electrochemical corrosion parameters. The initial resistance of the pores decreases from large to small and increases from small to small in the early stage of corrosion, so that the corrosion rate The main reason is that during the heat treatment, TiN oxidizes with O2 in the atmosphere to form a TiO2 phase and a Ti3O phase with a lower density than TiN, so that the coating layer Part of the through hole is closed, corrosion resistance can be improved.