The effect of segregation and thermodiffusion on the formation of interfaces in nanostructured (Ti–Hf–Zr–V–Nb)N multielement coatings

Superhard nanostructured multielement coatings based on (Ti–Hf–Zr–V–Nb)N composition have been studied before and after thermal annealing at 600$^\circ$C. It has been established that capture of positrons on defects takes place at the boundaries of nanograins and on interfaces (vacancies, nanopores, triple and higher-order joints of nanograins). Three-dimensional maps of the distribution of elements in super-hard coatings have been obtained using micro-proton-beam induced X-ray emission ($\mu$-PIXE) measurements. Analysis of the $\mu$-PIXE elemental profiles and defect profiles (obtained using a focused positron beam) helps understanding the physical picture of processes related to the formation of interfaces and sub-boundaries in nanostructured (Ti–Hf–Zr–V–Nb)N coatings.