Structural and mechanical properties of multilayer TiN/CrN coatings

Multilayer and superlattice coatings of TiN/CrN coating are deposited on Si(100) substrate at different modulation wavelength by reactive unbalanced magnetron sputtering and characterized using X-ray diffraction, nanoindentation, AFM. Nano-roughness of films is in good correlation with hardness and modulus and this effect has been used for optimization of deposition parameters. Preliminary results have shown slightly better mechanical properties for multilayered TiN/CrN coatings compared to single layer TiN and CrN coatings. The XRD results have shown a preferred orientation in 〈100〉 direction for TiN/CrN multilayer coatings at modulation wavelengths below 80 nm. At 100 nm layer thickness, TiN revealed small amount of crystals with 〈111〉 orientation and their content significantly increases with increase in layer thickness while CrN layers only show preferred orientation of 〈100〉. Multilayered coatings exhibit better mechanical properties due to presence of large number of interfaces which act as barrier to dislocations. Fracture toughness and tribological properties of these coatings are also expected to show significant improvement and the investigation in this area is under progress. Copyright © 2007 by ASME.