The phase evolution, microstructure and mechanical properties of CoCrFeMnNiTi_x (x = 0, 0.2, 0.4, 0.6, and 0.8 in molar ratio, denoted as Ti_x hereafter) high entropy alloy films (HEAFs) were studied in this work. The films were prepared by co-sputtering of CoCrFeMnNi alloy and Ti targets. Abundant nanotwins were observed in the Ti₀ and Ti_0.2 films and the crystalline structures of both films were identified to be a single FCC phase. In Ti_0.4 and Ti_0.6, the matrix exhibited an amorphous structure, and both the nanocrystalline grains and nanotwins were embedded in the amorphous matrix. With further addition of Ti, the Ti_0.8 film transformed to an amorphous structure. As a result, there was a phase transition from a single FCC to an amorphous structure with the increasing Ti content. Furthermore, nanoindentation tests showed that the hardness of the films increased from 6.62 GPa in Ti₀ to 8.99 GPa in Ti_0.8. Micropillar compression tests showed that the fracture strain decreased from >19.42% (no fracture) to 7.78% with the increasing Ti content. The best mechanical properties in compression were observed in Ti_0.4, and the compressive yield and fracture strengths were 2.82 and 4.44 GPa, respectively, with the fracture strain of 12.4%, which was achieved by a balanced amount of nanocrystalline grains in the amorphous matrix.

在这项工作中研究了CoCrFeMnNiTi _x（x  = 0、0.2、0.4、0.6和0.8摩尔比，以下称为Ti _x）高熵合金膜（HEAFs）的相演化，微观结构和力学性能。通过共溅射CoCrFeMnNi合金和Ti靶来制备薄膜。在Ti ₀和Ti _0.2薄膜中观察到了丰富的纳米孪晶，并且两个薄膜的晶体结构都被确定为单一的FCC相。在Ti _0.4和Ti _0.6中，基体呈现出非晶态结构，并且纳米晶粒和纳米孪晶均嵌入非晶态基体中。进一步添加Ti，Ti _0.8膜转变为非晶结构。结果，随着Ti含量的增加，存在从单一FCC到非晶结构的相变。此外，纳米压痕测试表明，膜的硬度从Ti _0中的6.62 GPa增加到Ti _0.8中的8.99 GPa 。微柱压缩试验表明，随着Ti含量的增加，断裂应变从> 19.42％（无断裂）降低到7.78％。在Ti _0.4中观察到了最佳的压缩机械性能，压缩屈服强度和断裂强度分别为2.82和4.44 GPa，断裂应变为12.4％，这是通过非晶态基体中均衡数量的纳米晶粒实现的。