The surface free energy of solids is a characteristic factor which affects the surface properties and interfacial interactions such as adsorption, wetting, adhesion etc. Therefore the surface free energy is of interest in the held or adhesive technologies, biomedical applications, cleaning procedures or for the wettability of tribological systems. One method of determining the polar and dispersive terms of the free surface energies of solids is based on measurements of the contact angles of pure liquids on solid surfaces. Within this paper the use of dynamic contact angle analysis for the evaluation of surface tension is described. PVD-coatings in the systems of Ti-Hf-N, Zr-C and Cr-AI-N were examined by using the dynamic contact angle analysis. The contact angles were measured by the sessile drop technique. The influences of chemical composition as well as macro- and microstructure on contact angles and surface tension were investigated. The test series presented here have shown that the surface free energy and above all its polar and disperse shares can be modified through the mechanical processing of hard metal samples, leading to different adhesions of the layer. The results show that a high polar share with a simultaneously high overall surface energy of the substrate lead to a better layer adhesion. Neither roughness nor phase structure, hardness or modulus of elasticity of the PVD layers investigated lead us to assume a correlation to the surface energy. It could be shown that adsorption and reaction layers lead to lower surface energies. The concomitant poorer wetting behaviour of the surfaces can significantly alter their useful and application features.