Structural stability and mechanical anisotropy of Ti(Si,V)N/SiNx interfaces
Self-lubricant coating systems with the release of the lubricious species have enormous potential to protect components working in extreme conditions combining high temperature and contact pressure. In our project, we investigate multifunctional Ti(Si, V)N nanostructured coatings with a microstructure established in a super hard class of the TiN/SiNx nanocomposites and an ability to control the formation of V2O5 surface oxide acting as a solid lubricant to extend the lifetime of cutting tools. The tailoring of the thickness of a (quasi)amorphous SiNx matrix to control the transport of vanadium to the surface coating, where a low-friction solid/liquid V2O5 tribolayer is formed during operation. In the present work, we report on state-of-the-art DFT and Molecular Dynamics calculations revealing the structure and stability of the TiN/SiN and Ti(Si, V)N/SiN interfaces. The special attention is given to the stability of interfaces as a function of the thickness of the amorphous SiN tissue. The detailed analysis of the structure, stability and mechanical anisotropy of layered TiN/SiN and VN/SiN films with amorphous and crystalline SiNx (with various compositions) will be discussed. The presented results form a basis for the understanding of the microstructural impact on the transfer kinetics of V towards the film surface at elevated temperatures.