Structure and Properties of Multi layer Nanostructured Coatings TiN/MoN Depending on Deposition Conditions

This work presents the results of TiN/MoN coatings studying. These multilayer nanostructured coatings demonstrate dependence on depositions conditions on nanometer level. The influence of nanosized monolayer thickness on structure changing and properties of nanocomposite multilayer coatings TiN/MoN was found. Multilayer TiN/MoN coatings of the total thickness from 6.8 to 8.2 mu m were obtained using C-PVD method. Thicknesses of monolayers were 2, 10, 20, 40 nm. The structure of samples was studied using X-ray diffraction (Bruker D-8 Advance) in Cu K alpha radiation, high resolution transmission electron microscopy with diffraction CFEI EO Techai F200, scanning electron microscopy with energy dispersive X-ray spectroscopy (JEOL-7001F), and microhardness measurements in dependence on indenter load. Scratch tests (friction, wear, etc.) were also provided using Rockwell-C diamond indenter (CSM Revetest Instruments) with a tip radius of 200 mu m. Friction and wear behavior were evaluated using ball-on-plate sliding test on a UMT-3MT tribometer (CETR, USA). With decreasing monolayer thickness the hardness value increases, and the size of nanograins reduces. The values obtained for the friction coefficient of the multilayer system is much smaller than in nanostructured coatings of TiN (nc) or MoN (nc). Annealing showed formation of a (Ti,Mo)N solid solution and small growth of nanocrystals.