Vanadium carbide/titanium carbide (VC/TiC) superlattice films were synthesized by magnetron sputtering method. The effects of modulation period on the microstructure evolution and mechanical properties were investigated by EDXA, XRD, HRTEM and nano-indentation. The results reveal that the VC/TiC superlattice films form an epitaxial structure when their modulation period is less than a critical value, accompanied with a remarkable increase in hardness. Further increasing the modulation period, the hardness of superlattices decreases slowly to the rule-of-mixture value due to the destruction of epitaxial structures. The XRD results reveal that three-directional strains are generated in superlattices when the epitaxial structure is formed, which may change the modulus of constituent layers. This may explain the remarkable hardness enhancement of VC/TiC superlattices.%采用磁控溅射工艺制备VC/TiC超晶格薄膜，并采用EDXA、XRD、HRTEM和纳米力学探针研究调制周期对超晶格薄膜的微结构和力学性能的影响。研究结果表明，当超晶格薄膜的调制周期低于临界厚度时，制备的VC/TiC超晶格薄膜能够形成共格生长结构，并获得硬度显著提高的超硬效应。然而，随着调制周期的进一步增大，超晶格薄膜的共格结构遭到破坏，导致薄膜的硬度逐渐降低，并最终趋于其组元的混合平均值。XRD结果表明，当形成共格生长结构时，超晶格薄膜内部将产生共格协调应变，从而改变不同调制层的弹性模量，这也是VC/TiC超晶格薄膜能够获得超硬效应的重要原因。
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