Abstract
The microstructure and mechanical properties of a periodically alternating multilayered nanostructured coating composed of alternating metal nitrides (CrN/ZrN) and pure metals (Cr/Zr) were investigated. A specially designed multilayer structure was fabricated, consisting of 7 metal and 40 nitride layers within one modulation period. The thickness of each metal layer was 16 nm, while the thickness of each nitride layer was 25 nm. To explain the mechanism of increased coating strength, first-principles calculations were conducted based on the obtained experimental results. Microstructural studies revealed that cubic CrN and ZrN phases predominate, clearly oriented along the (200) and (111)/(200) crystallographic directions. Despite the nanoscale dimensions of the nanolayers and nanocrystals, dislocations and structural disorder of crystal planes were observed at the interfaces between CrN and ZrN layers. The investigated multilayer structure demonstrated outstanding mechanical properties, including a maximum hardness of 34 GPa, a reduced elastic modulus of 330 GPa, an elastic strain limit before plastic deformation of 0.1, and a plastic deformation resistance of 0.36. These superior properties were achieved as a result of the unique multilayered (internal multilayer) architecture of the coating and its specific structural features.