共溅射Al-Zr合金薄膜的非晶化及其力学性能

Amorphizing and mechanical properties of co-sputtered Al-Zr alloy films

为研究合金薄膜非晶化后力学性能持续提高的原因,通过双靶磁控共溅射方法制备了一系列不同Zr含量的Al-Zr合金薄膜,采用EDS,XRD,TEM和纳米力学探针表征了薄膜的微结构和力学性能.结果表明:在溅射粒子高分散性和薄膜生长非平衡性的共同作用下,较低Zr含量的薄膜形成超过饱和固溶体,剧烈的晶格畸变使薄膜的晶粒纳米化,其硬度相应迅速提高.随Zr含量的进一步增加薄膜形成非晶结构,非晶薄膜的硬度因Al-Zr键数量的增加持续提高,并在含33.3 at.%Zr达到9.8 GPa后增幅减缓.研究结果揭示了非晶薄膜中Al-Zr键对薄膜力学性能的显著作用.

In order to reveal the reason why mechanical properties of alloy films increase continuously after amorphizing, a series of Al-Zr alloy films with different Zr contents are prepared by magnetron co-sputtering of Al and Zr targets. The microstructure and mechanical properties of the films are characterized through a number of techniques, including X-ray energy dispersive spectroscopy, X-ray diffraction, transmission electron microscopy, and nanoindentation. Results show that the films with low Zr content form highly supersaturated solid solutions due to high dispersibility of vapor particles and non-equilibrium growth of the film in co-sputtering process. The film grains are refined to nanoscale particles due to dramatic lattice distortion and the film hardness increases rapidly. As Zr content increases, the film hardness increases continuously because of the increase of Al-Zr chemical bonds after amorphizing, and reaches a high value of 9.8 GPa at 33.3 at.%Zr. The research results reveal the effect of the Al-Zr chemical bonds on mechanical properties in amorphous films.