Size dependent strengthening mechanisms in sputtered Fe/W multilayers

作者：Li Nan; Yu K Y; Lee J; Wang H; Zhang X^*

来源：Journal of Applied Physics, 2010, 107(9): 093503.

DOI：10.1063/1.3400130

We investigate size dependent strengthening mechanisms in sputtered Fe/W multilayers with individual layer thickness, h, varying from 1 to 200 nm. Microstructure analyses reveal that Fe/W has incoherent bcc/bcc interface when h is greater than 5 nm. When h decreases to 1-2.5 nm, the interface becomes semicoherent, and Fe and W show significant lattice distortions comparing to their bulk counterpart due to interface constraint. The layer thickness dependent drastic variations in x-ray diffraction profiles are simulated well by using an analytical model. Film hardness increases with decreasing h, and approaches a maximum value of 12.5 GPa when h is 1 nm. The layer thickness dependent film hardnesses are compared with analytical models. Koehler';s image force plays a major role in determining the maximum strength of composites at smaller h.

• 出版日期2010-5-1