多弧离子镀与磁控溅射共沉积TiCN薄膜的耐蚀性研究

Study of corrosion resistance of TiCN films with combining multi-arc ion plating and magnetron sputtering technique

摘要:

采用多弧离子镀-磁控溅射复合技术在AISI304不锈钢基体表面于Ar和N2混合气氛下共溅射钛靶和石墨靶制备了TiCN薄膜，研究了占空比对TiCN薄膜结构和在3.5 wt.%NaCl 中耐蚀性的影响规律。结果表明:所沉积的TiCN薄膜表面光滑、均匀致密，主要形成具有 Ti-(C,N) 键的fcc-TiN型结构和少量的a-CNx化合物，并随着占空比的增加表现出（111）晶面择优取向。TiCN薄膜相比于基体表现出更好的耐蚀性能，且随着占空比的增大，薄膜的耐蚀性逐渐提高。当占空比为40%时，TiCN薄膜表现出最为优异的抗腐蚀性能，其自腐蚀电流密度(icorr)和极化电阻(Rp)分别为3.262×10-7 A.cm-2和238.4 kΩ.cm2。薄膜的阻抗谱显示腐蚀离子的渗透行为和局部腐蚀过程是影响电极体系腐蚀反应过程中的主要动力学因素，这与极化曲线的分析结果相一致。

关键词:TiCN薄膜; 多弧离子镀和磁控溅射技术; 占空比; 耐蚀性

Abstract:

TiCN films were deposited on AISI 304 stainless steel substrate by combining multi-arc ion plating and magnetron sputtering technique with ionizing titanium and graphite targets in an Ar+N2 mixture gas. The effect of duty ratio on the microstructure and corrosion resistance performance of TiCN films in a NaCl 3.5 wt.% solution was investigated. The results show that the as-deposited films reveal smooth, uniform and dense morphologies, mainly forming a fcc-TiN type structure with Ti-(C,N) bond as well as few a-CNx, and presenting (111) preferred orientation with the increase of duty ratio. TiCN films display a better resistance to corrosion than the bare substrate, as the duty ratio increased, the corrosion resistance property is enhanced gradually. When the duty ratio is 40%, the TiCN film shows the optimal one with a corrosion current density (icorr) of 3.262×10-7 A.cm-2 and a polarization resistance (Rp) of 238.4 kΩ.cm2, respectively. Electrochemical impedance spectroscopy (EIS) of the films also indicate that the penetration behavior of corrosive ions and the local corrosion process are two key factors affecting the electrode corrosion reaction kinetics process, which is in agreement with the polarization curves analysis results.

Key words:TiCN films; multi-arc ion plating and magnetron sputtering technique; duty ratio; corrosion resistance