调制周期对TiN/Ti多层膜组织结构和结合力的影响

为了阐明调制周期对薄膜微观组织及薄膜与基体结合力的影响,采用反应磁控溅射在Ti6Al4V基板上交替沉积了Ti层及TiN层制备了TiN/Ti多层膜。利用X射线衍射仪(XRD)、扫描电子显微镜(SEM)、显微硬度仪和划痕仪测量分析了薄膜的晶体结构、微观组织、硬度以及薄膜与基体之间的结合力。研究结果表明:TiN/Ti多层膜中均存在TiN,Ti和Ti2N 3种相。TiN/Ti多层膜均以柱状晶方式生长,在调制周期较大(5层)时,TiN和Ti层的界面清晰;随着调制周期的减小(层数增加),TiN和Ti层的界面逐渐消失。与单层TiN薄膜相比,多层TiN/Ti薄膜的硬度显著提高;但随着薄膜层数的增加,多层TiN/Ti薄膜硬度略微降低。当调制周期为80nm(30层)时,薄膜与基体的结合力明显提高,达到73N。

Effects of Modulation Periods on Structure and Adhesion Strength of TiN/Ti Multilayer Films

TiN/Ti multilayer films were deposited on Ti6Al4V substrate by alternatively depositing Ti layer and TiN layer in a reactive magnetron sputtering system, in order to explore the effects of modulation periods on microstructure and adhesion strength between films and substrate. The crystal structure, microstructure, hardness and adhesion strength between the films and the substrate were investigated by XRD, SEM, microhardness instrument and scratch test apparatus, respectively. The results show that all the TiN/Ti multilayer films contain three phases: Ti, TiN and Ti2N. SEM characterization shows that all the TiN/Ti multilayer films are column microstructure. For the films with high modulation period (5 layers), the interfaces between the Ti layer and the TiN layer can be clearly seen. With the decrease of the modulation period (increase of layer number), these interfaces gradually disappear. The microhardness of the TiN/Ti multilayer thin films is higher than that of the TiN single layer films. However, for the TiN/Ti multilayer thin films, with the increase of the number of layers, the microhardness slightly decreases. In addition, the adhesion strength of the TiN/Ti multilayer thin films with 30 layers is up to 73 N, which is much higher than that of the TiN single layer films.