通过TiB₂和Al共溅射方法制备了约7.1%TiB_x (原子分数)的铝基复合薄膜, 采用三维原子探针并结合X射线衍射仪、透射电子显微镜和微力学探针表征了薄膜的微结构和力学性能. 结果表明, 在溅射粒子的高分散性和薄膜生长的非平衡性共同作用下, TiB₂靶的溅射粒子以TiB_x化合物的形式被超过饱和地固溶于Al的晶格中, Al固溶体晶粒细化为纳米晶并逐步非晶化, 薄膜形成了较低溶质含量(约2%TiB_x)纳米晶弥散分布于高溶质含量非晶基体中的两相结构并获得高硬度.结合实验结果讨论了超过饱和固溶体薄膜微结构形成的热力学和动力学原因.

In order to reveal the solute existing form and its effect on the microstructure and mechanical properties in the supersaturated solid solute films, TiB_x/Al composite film with 7.1%TiB_x (atomic fraction) was synthesized by magnetron co-sputtering using Al and TiB₂ targets. The microstructure and mechanical properties of the film were characterized by 3D atom probe cambined with X-ray diffraction, transmission electron microscopy and nanoindentation. The results reveal that TiB_x compounds were largely dissolved in the Al lattice due to atomic mixing and sufficiently low mobility of the atoms during growth. The film grain was refined to nanoscale and amorphous gradually result from the severe lattice distortion. The film consisted of a two-phase structure in which lower solute content (about 2%TiB_x) nanocrystals dispersed in amorphous matrix with a higher solute content and gained high hardness. Combined with the experimental results, the microstructure formation of the composite films was discussed from thermodynamic and kinetic aspects. This study provided the direct experimental evidence of compound dissolved in highly supersaturated solid solution.