Cu-Ti合金薄膜的微结构和力学性能

通过磁控共溅射方法制备了一系列不同Ti含量的Cu-Ti合金薄膜,采用EDS、XRD、TEM、AFM和纳米力学探针表征了薄膜的微结构和力学性能,研究了化合物对超过饱和固溶薄膜的强化作用。结果表明,由于溅射粒子的高分散性和薄膜生长的高非平衡性,Cu-Ti薄膜形成了超过饱和固溶体,晶格的剧烈畸变使Cu固溶体晶粒迅速细化。随Ti含量的增加,薄膜中产生高分散的细小Cu Tix化合物,并逐步形成Cu超过饱和固溶体纳米晶和细小化合物分布于非晶基体中的结构。与微结构的变化相应,薄膜的硬度随Ti含量的增加持续提高,并在含21.4%Ti(原子分数)时达到8.7GPa的最高值。高分散金属间化合物的存在是Cu-Ti合金薄膜在形成非晶结构后硬度得以继续提高的原因。

Microstructure and Mechanical Properties of Cu-Ti Alloy Films

A series of Cu-Ti alloy thin films with different Ti contents were prepared by a magnetron co-sputtering method. The microstructure and mechanical properties of the thin films were characterized through a combination of techniques, including X-ray diffraction, transmission electron microscopy, atomic force microscopy and nanoindentation. The strengthening effect of compounds on supersaturated solid solution films has been investigated. The results show that supersaturated solid solution forms in Cu-Ti films due to high non-equilibrium growth of films and high dispersibility of sputtered particles during the sputtering process. The grains of Cu solid solution are refined rapidly because of the dramatic lattice distortion. Highly disperse fine CuTix compounds appear with Ti content increasing. Supersaturated solid solution nanocrystalline and fine compounds distributed in the amorphous matrix occur gradually in the films. Corresponding to the change of the microstructure, the films hardness increases continuously with Ti content increasing and reaches a maximum value of 8.7 GPa at 21.4at%Ti. The Cu-Ti film strengthening after forming amorphous structure is attributed to highly dispersed intermetallic compounds