Application of Vickers indentation for assessment of PVD TiN coated new nonledeburitic high-speed steels

The work is focused on the application of Vickers method for assessment of PVD coated high-speed steels. New grades of tailored carbide phase and commercial steels, both wrought and by powder metallurgy, were coated with titanium nitride. Indentations made at a wide range of loads were employed to obtain the coatings hardness using both theoretical models and an extrapolation method. On the basis of scanning electron microscope observations, fracture patterns were classified and quantitative criteria for their evaluation were suggested. The indentation measurements were used to assess the influence of the steel substrate material, coating thickness and presence of Ti underlayer on cohesion and adhesion of the coatings.