Multilayer composite ceramic-metal thin film: Structural and mechanical properties

Multilayer coatings with combination (10 BL, 20 BL and 30 BL) of transition-metal nitride (tungsten nitride, W2N) and ductile interlayers (Ti, Ni) were deposited by reactive DC magnetron sputtering technique on silicon substrates. Structural and mechanical properties of the deposited samples were analyzed by grazing incidence Xray diffraction (GIXRD), field emission scanning electron microscope (FESEM), energy dispersive X-ray analysis (EDX) and nanoindentation tests. GIXRD result confirms the presence of cubic W2N phase. FESEM image shows periodic arrangement of W2N and (Ti, Ni). Mechanical parameters like hardness, elastic modulus and resistance to plastic deformation were calculated. The effect of different factors e.g. ceramic/metal ratio, interlayer material and interface on mechanical properties were discussed. These results indicate that these factors play a dominant role in defining mechanical properties. The best mechanical properties were observed for 20 BL in comparison with 10 BL and 30 BL coating and has been attributed to higher ceramic to metal thickness ratio.