磁控溅射(Ti,N)/Al纳米复合薄膜的微结构和力学性能

采用Al和TiN靶通过磁控共溅射方法, 制备了一系列Ti:N≈1的不同(Ti, N) 含量的铝基纳米复合薄膜, 利用X射线能量分散谱仪、X射线衍射仪、透射电子显微镜和纳米力学探针表征了薄膜的成分、 微结构和力学性能, 研究了(Ti, N)含量对复合薄膜微结构和力学性能的影响. 结果表明: Ti, N原子的共同加入使复合薄膜形成了同时具有置换固溶和间隙固溶特征的"双超过饱和固溶体", 薄膜的晶粒随着溶质含量的增加逐步纳米化, 并进一步形成非晶结构, 晶界区域形成溶质原子的富集区. 相应地, 复合薄膜的硬度在含1.8 at.%(Ti, N) 时就可迅速提高到3.9 GPa; 随着TiN含量的增加, 薄膜的硬度进一步提高到含17.1 at.%(Ti, N)时的8.8 GPa. 以上结果显示出Ti和N"双超过饱和固溶"对Al薄膜极其显著的强化效果.

Microstructures and mechanical properties of (Ti, N)/Al nanocomposite films by magnetron sputtering

A series of aluminum matrix nanocomposite films are synthesized by magnetron sputtering of Al and TiN targets. The composition, microstructure and mechanical property of the composite film are characterized by energy dispersive spectroscopic, X-ray diffraction, transmission electron microscope and nanoindenter. The influences of (Ti, N) content of supersaturated solute Ti,N atoms on the microstructure and mechanical property of the composite films are investigated. The results reveal that the composite film with adding Ti,N atoms together forms a dual-supersaturated solid solution exhibiting both features of substitutional and interstitial solid solution. Higher solute content induced gradual evolutions of nanocrystallization and amorphization of grains in film and solute enrichment occured at the grain boundaries. Correspondingly, the composite film containing 1.8 at.% (Ti, N) can rapidly reach a hardness of 3.9 GPa, and further increasing TiN content to 17.1 at% (Ti, N) the film hardness achieves 8.8 GPa demonstrating the significant strengthening effect of dual-supersaturation of Ti and N on aluminum film.