Microstructure and properties of metal/ceramic and ceramic/ceramic multilayer coatings on titanium alloy Ti6Al4V

The results revealed that the obtained multilayer coatings differed in microstructure due to the different type of interfaces. Coherent, semi-coherent interfaces or interfaces with a transition layer influence the growth mechanism of the coatings and affect grain size. The investigation revealed that the grain size of the coatings also depends on the bi-layer period (number of layers). However, this effect was opposite for the metal/ceramic and ceramic/ceramic coatings due to the type of interface. The results showed that increasing the number of layers improved the mechanical properties of the Cr/CrN multilayer coatings. However, this relationship was not observed for CrN/TiN.