结构调制超硬Ti/TiN纳米多层膜的制备及其尺寸效应

使用多弧离子镀技术在高速钢基体上制备了调制周期为5~40 nm的Ti/TiN纳米多层膜，用扫描电子显微镜(SEM)、X射线能谱仪(EDS)、X射线衍射仪(XRD)、纳米压痕仪和划痕仪等手段表征薄膜的微观结构和性能，研究了调制周期对Ti/TiN纳米多层膜性能的影响，并讨论了在小调制周期条件下Ti/TiN纳米多层膜的超硬效应和多弧离子镀技术对纳米多层膜硬度的强化作用。结果表明，与单层TiN相比，本文制备的Ti/TiN纳米多层膜分层情况良好，薄膜均匀致密，没有明显的柱状晶结构，TiN以面心立方结构沿(111)方向择优生长。随着调制周期的减小薄膜的硬度呈现先增大后减小的趋势，并在调制周期为7.5 nm时具有最大的硬度42.9 GPa和H/E值。这表明，Ti/TiN在具有最大硬度的同时仍然具有良好的耐磨性和韧性。Ti/TiN纳米多层膜的附着力均比单层TiN薄膜的附着力高，调制周期为7.5 nm时多层膜的附着力为(58±0.9) N。

Preparation of Structure-Modulated Superhard Ti/TiN Nano-Multilayers and Size Effect

Multilayered films Ti/TiN with 5~40 nm modulation period were prepared on a high-speed steel substrate by multi-arc ion plating technology. The microstructure and mechanical property of the films were characterized by means of scanning electron microscopy (SEM), X-ray energy dispersive spectrometer (EDS), X-ray diffraction (XRD), nanoindentation and scratch test. The effect of modulation period on the performance of multilayered films Ti/TiN was investigated. Results show that the multilayered films Ti/TiN are uniform and dense with lamellar structure but without obvious features of columnar structure. TiN film is preferentially grown along the (111) direction. The film hardness increases firstly and then decreases with the decrease of the modulation period. The maximum hardness of 42.9 GPa and the maximum H/E value werer obtained when the modulation period is 7.5 nm, which indicates that the film possesses good combination of wear resistance and toughness. In addition, the adhesion of the multilayered films Ti/TiN is generally higher than that of the single-layered TiN film. When the modulation period is 7.5 nm, multilayered films Ti/TiN present a relatively high adhesion of (58±0.9) N.