AFM of titanium nitride layers prepared under glow discharge conditions

Optimization of titanium-based materials for medical application is a complex task linking specialists in various disciplines. This is a consequence of a system of self-dependent critical conditions required for their application. It is well known that majority of processes proceeding in the human body occur at surfaces and interfaces. Hence the knowledge concerning surfaces of the applied materials is essential for understanding the occurred processes and for optimization of the applied material. In this paper the atomic force microscopy was applied for investigation of the surface topography of nitrided layers of titanium alloys in a nano and mezoscopic scale. Topography of layers nitrided at temperatures: 730, 850 and 1000 °C were compared. Results indicate that the size and distribution of the grains structure formed during nitriding processes strongly depends on the preparation temperature. This observation is related with the differences in chemical composition. The most appropriate temperature from the point of view of surface homogeneity is 850 °C. This conclusion correspond with the results of biological investigations which showed that layer of titanium nitride prepared at this temperature is characterized by the maximal biocompatibility [E. Czarnowska, T. Wierzchoń, A. Maranda-Niedbała, E. Kaczmarewicz, J. Mater. Sci.: Mater. Med. 11 (2000) 1].