Наноструктурные и нанокомпозитные сверхтвердые покрытия

Electron microscopy, X-ray structural analysis, and microhardness and nanohardness measurements are used to investigate special features of the interrelation between the fine substructure and variation in strength properties of single-phase (TiN) and nanocomposite coatings (TiN/Cu, AlN/Cu, Ti-Si-B-N) in the vicinity of the coating substrate interface and on the coating surface. It is shown that a two-level grain structure with grains 0.1÷0.3 nm in size fragmented into subgrains 0.15÷0.25 nm in size with small angle misorientations Δφ ≤ 5° is found in TiN, TiN/Cu and Ti-Si-B-N coatings. In nanocomposite TiN/Cu coatings the initial hardness Hμ ~ 40 GPa decreases to 20÷22 GPa owing to ageing at T ~ 300 K for t≥ 4 103 h and internal stresses measured by lattice bending-torsion relax. Ti-Si-B-N coatings admixed with oxygen and carbon are characterized by stable values of Hμ ≈ 55÷60 GPa in structural states corresponding to the two-level grain structure of silicon-doped titanium nitride and amorphous grain-boundary phases. In AlN/Cu coatings at a uniform distribution of aluminum nitride nanograins (d Hμ = 12÷15 GPa is governed by a high volume fraction of the metal phase. In the paper we analyzed the application prospects of nanocoatings of types MeN/metal and MeN/amorphous phase (Me-Ti, Zr, V, W, Cr).