Structure, hardness and adhesion of thin coatings deposited by PVD, IBAD on nitrided steels

Abstract

The paper discusses microstructure, mechanical and physical testing with several examples of advanced coating systems. Another development for use with the plasma nitriding system is surface deposition after the nitriding treatment. This allows nitriding to be carried out in the plasma nitriding chamber followed by a surface deposition treatment, such as depositing titanium nitride. Samples were plasma nitrided at different thickness of plasma surface layers. TiN was deposited with classics BALZER PVD equipment. The other samples were produced with IBAD technology in DANFYSIK chamber. The properties and quality of ion beam-assisted deposition (IBAD) coatings depend on many process parameters, such as the ion energy, ion to atom arrival ratio, angle of ion incidence, pressure, temperature, etc. This is the reason why IBAD coatings must be planned very accurately. X-ray diffraction studies were undertaken in an attempt to determine the phases present, and perhaps an estimate of grain size from line broadening. The surface roughness was measured using stylus type (Talysurf Taylor Hobson) instruments. The coating morphology was evaluated (with SEM), using the well-known structure zone model of Thornton. The present coating method can produce dance structures, high hardness and the high-critical load values can be achieved. © 2004 Elsevier Ltd. All rights reserved.