磁控溅射(Ti,Al)N纳米晶薄膜的结构和性能

Microstructure and Properties of Magnetron Sputtered Nanocrystalline(Ti,Al)N Thin Film

通过在N2气氛和600℃基体温度下交替溅射Ti和Al靶并通过沉积过程中Ti和Al原子间的互扩散制备了(Ti,Al)N纳米晶薄膜.采用场发射扫描电镜、X射线衍射和纳米压痕技术研究了薄膜的微结构和力学性能.结果表明,(Ti,Al)N膜具有细小、致密和光滑的表面结构.在交替沉积过程中Ti原子会被较小的Al原子取代,形成面心立方结构的(Ti,Al)N薄膜,并存在(200)面择优取向.与TiN薄膜相比,(Ti,Al)N薄膜的晶粒尺寸和晶格常数均有所下降;(Ti,Al)N薄膜的硬度H明显提高,而弹性模量E却稍有降低,其结果使H3/E2比值大幅提高,薄膜的抗塑性变形能力增强.(Ti,Al)N纳米晶薄膜的高性能主要归因于固溶强化机制.

Nanocrystalline（Ti,Al）N thin film was prepared by alternatively sputtering Ti and Al targets in N2 gas atmosphere at 600℃,and by mutual diffusion between Ti and Al atoms during film deposition.The microstructure and mechanical properties of the deposited films were investigated by field emission scanning electron microscopy,X-ray diffraction and nanoindenter.The deposited film surface was smooth and dense with an obvious column grain growth.The preferential orientation of the（Ti,Al）N and TiN films was（200）plane,and the lattice constant reduced when Al was added,associated with Ti atom substitution by smaller Al atoms during alternative deposition. The nanohardness of the（Ti,Al）N films greatly increased while the elastic modulus slightly decreased and thus H^3/E^2 value greatly increased compared to the TiN film.The enhancement of nanocrystalline（Ti,Al）N film was interpreted in terms of solid solution hardening effect.