TiN/CrN多层薄膜微观结构与力学性能的研究

Microstructure and Mechanical Properties of TiN/CrN Multilayer Films

摘要:

近些年来,TiN/CrN多层薄膜由于其优良的力学性能被广泛应用于表面防护,提高零部件性能和使用寿命等方面。为了研究TiN/CrN多层薄膜微观结构与力学性能的关系,本文采用磁控溅射技术制备了TiN、CrN单层薄膜和三种不同调制周期的TiN/CrN多层薄膜。通过原子力显微镜和X射线衍射分析了膜的表面形貌和相结构。使用纳米压痕仪测试薄膜的硬度和压入塑性,曲率法测定薄膜的残余应力。结果表明,TiN/CrN的多层薄膜是由TiN和Cr2N两相组成,随着调制周期的增大TiN层与CrN层之间的界面区域变小,界面平滑且明显。力学性能方面,多层薄膜的硬度和压入塑性比单层膜好,并且多层薄膜随调制周期的减小硬度和压入塑性越大,残余应力随周期性的增加而逐渐增大。综上可见,TiN/CrN多层薄膜的力学性能的改善取决于界面区域的大小和形貌,即调制周期,该结论与Hall–Petch理论相吻合。

Abstract:

During the last past decades, TiN/CrN muiltilayer coatings have been extensively developed to improve the performance and lifetime of components due to their excellent mechanical properties. In order to study the relationship between mechanical properties and microstructure of TiN/CrN multilayer coatings, the TiN, CrN film and threeTiN/CrN multilayer films with different periodicities were prepared on monocrystalline silicon by magnetron sputtering. Atomic Force Microscope and X-ray diffraction were adopted to analyse the surface morphology and chemical construction of the films. The hardness and indentation plasticity were studied using nanoindenter. Residual stress was measured by curvature method. The results show that TiN/CrN multilayer films exhibit a mixture of TiN and Cr2N phases, the interface zone between TiN layer and CrN layer become small and sharp with the increasing of periodicity. Hardness and indentation plasticity of multilayer films are better than monolayer films, and increase as the bilayer period decreases. For multilayer films, the residual stress increases gradually with the increasing of periodicity. From the above observation, it can be concluded that the improvement in mechanical property depend on minor periodicity. The results agree well with Hall–Petch theory.