Morphological, Structural and Tribological characterisation of pulsed laser deposited titanium nitride coatings
Publication from Materials
Praktische Metallographie 41 (10), pp. 481-493, 2004
Because of its high hardness and low wear rates titanium nitride (TiN) is the most widespread material for hard coatings. Thin TiN films have been deposited industrially in recent years with various deposition methods. For coating of heat sensitive materials and machine parts at low temperatures down to room temperature only a few deposition techniques can be applied. One of these is the pulsed laser deposition (PLD) method, which was used in this work for the deposition of TiN thin films on three-dimensional shaped substrates.
A Nd:YAG laser of 1064 nm wavelength was applied to vaporize titanium targets in low pressure N2 atmospheres at room temperature. As substrate materials for the deposition of the TiN films a high speed tool steel (DIN 1.3343) and a corrosion resistant steel (DIN 1.4542) were used. The substrate surfaces were situated parallel (on-axis) and rectangular (off-axis) to the target surface to simulate film deposition on three-dimensional shaped tools. The films were examined by light-microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), nano-indentation and pin-on-disk tests. The results indicate, that the PLD method is suitable for deposition of crystalline, strong textured TiN films with a very low surface roughness, with an excellent adhesion to the substrates, with a high hardness and a high wear resistance.