Structure and Properties of Vacuum Arc Single-Layer and Multiperiod Two-Layer Nitride Coatings Based on Ti(Al):Si Layers

Abstract

The paper provides an analysis of impact of deposition conditions on structural and phase state and thermal stability of vacuum arc coatings based on Ti(Al):Si layers. We studied single-phase single-layer coatings, and multiperiod bilayer coatings with second phase nitride interlayers of one of the following three metals: Mo, Cr or Zr. It was established that hexagonal and cubic lattices may form in the coatings when transition to the cubic lattice occurs with Al content of about 25 at. %. Presence of second nanoscale (7-8 nm) layers in bilayer multiperiod compositions, which consist of one nitride from CrNx, MoNx or ZrNx group, does not change the type of lattice in [Ti(Al):Si]Nx layers. Also, an fcc lattice with a strong or weak texture [111] forms in CrNx and ZrNx layers, while crystallites with hexagonal lattice form in MoNx layers. High-temperature annealing at 700 °С during 40 minutes leads to a significant (by 23 % or up to Н  47.56 GPa) increase in microhardness of coating of the [Ti(Al)]Nx/ZrNy system due to formation of a nano-size structure with an average size of crystallites of 3.6 nm in [Ti(Al)]Nx layers, and 6.3 nm in ZrNx layers.

(TiZr)N/(TiSi)N Maitilayer Nanostructured Coatings obtained by Vacuum Arc Deposition

“…One of the most promising trends in improvement of performance of nanostructured nitride coatings is creating of multilayer compositions with nanometer-thick layers [4][5][6]. In such a case, properties of the system, including emerging internal stresses and their concentration, or crack growth and proliferation, can be significantly changed through interchange of two and more layers of material with different stress-strain performance, which makes it possible to increase fracture toughness in such materials [7,8].…”