Microstructure evolution and mechanical properties in VC/SiC nanomultilayers

► VC can serve an excellent job as template materials, and this provides new evidences for the universality of template effect. ► The as-deposited amorphous SiC layers can be crystallized and grow coherently with VC layers even their lattice mismatch reaching 5.3%. ► Multilayers with high hardness can be obtained by proper design of microstructure in nanometer scale. A series of VC/SiC nanomultilayers were synthesized by magnetron sputtering techniques at a substrate temperature of 450°C. The microstructure and mechanical properties of the multilayers were studied by X-ray diffractometer, high-resolution transmission electron microscopy and nanoindentation device. The results showed that when the SiC layer thickness was below 0.7nm, the as-deposited amorphous SiC layers were crystallized and grew coherently with VC layers under the template effect of VC layers, accompanied by a remarkable increase in hardness. Further increasing SiC layer thickness, however, the epitaxial growth structure of the multilayers has been disrupted leading to the decrease of hardness.