电弧离子镀方法制备的Ti/TiN多层膜的结构与耐腐蚀性能

采用电弧离子镀技术,通过周期性变换环境气氛,在7075Al合金上制备了Ti/TiN多层膜,并研究调制周期对多层膜的结构组成和腐蚀性能的影响。结果表明:多层膜与铝合金衬底界面结合较好,基本没有孔洞等缺陷。多层膜具有明显的层状特征,层间界面清晰。多层膜中TiN与单层中TiN薄膜有着相同的晶体结构,并存在(111)择优取向,每个调制周期内的TiN层都呈柱状生长。随着调制周期变小,多层膜阳极极化曲线的腐蚀电位增加,交流阻抗谱的阻抗值增大,容抗弧的半径也增大,即膜层的耐腐蚀性增加。多层膜调制周期的减小使得薄膜中含有的层界面增多,而贯穿至衬底表面的针孔等缺陷的数量将减少,这样,腐蚀性介质经过针孔等缺陷与衬底接触的机会变少,这将使薄膜的抗腐蚀能力得到改善。

Structure and corrosion properties of Ti/TiN multilayers prepared by arc ion plating

The Ti/TiN multilayers were prepared using cathodic arc ion plating on 7075 Al alloy by periodically adjusting the environmental atmosphere,and the influence of the modulation period on their structure and corrosion properties was studied.There basically are no defects,such as pinholes,on the interface between multilayers and Al alloy substrate and the adhesion is high.The multilayers characterize the obvious layer growth and there is a clear interface between the individual layers.The TiN individual layer in multilayers has obvious(111) preferred grain orientation as same as single TiN film.The TiN individual layer in every modulation period grows in column characteristic.The corrosion potential of polarization curves,electrochemical impedance and radius of capacitive reactance increase respectively,namely,the corrosive resistance of multilayers improves,with shortening the modulation period.The corrosive resistance of the small modulation period films is improved because more interfaces reduce the chance of the contact between the corrosive solution and substrate by decreasing the quantity of penetrating pinholes and defects.