Tribological aspects of AlN-TiN thin composite films

Physical properties, and the friction and wear are important issues in small-scale applications, it is therefore essential that the materials used have good micromechanical and tribological properties. The adhesion, fracture toughness and wear properties of AlN-TiN thin composite films is being investigated in this study. The multilayered structures are generated using Pulsed Laser Deposition (PLD). The durability and functionality of thin films is subject to the adhesion between the coating and the underlying substrate in addition to it's resistance to cracking. The magnitude of the critical load during a scratch test is related to the adhesion of the substrate to the coating. In this test a Berkovich indenter is used for measurements and is drawn across the surface of a coating under an increasing load. The magnitude of the critical load will be studied for various films from a monolayer TiN film to different AlN-TiN films and those relative results compared to their facture toughness and their wear properties. Despite the adhesion, the critical load depends on several other parameters including the friction coefficient. The critical characteristic load is shown to depend on the number of layers and the relative AlN-TiN thickness. The fracture toughness showed a weak dependence on the layer characteristics. © 2005 Materials Research Society.