The structure and the corresponding mechanical properties of magnetron sputtered TiN–Cu nanocomposites

The present paper describes experimental studies of the structure and the corresponding mechanical properties of TiN–Cu nanocomposites synthesised by reactive magnetron sputtering. By X-ray diffraction, the crystalline phases appearing, the texture, the grain size and the microstrain were studied as a function of the deposition temperature and the substrate bias voltage. In addition, the nanostructure was studied by cross-section transmission electron microscopy and the surface morphology by scanning electron microscopy. At low deposition temperatures, a two-phase structure consisting of a fcc TiN phase and a highly disordered crystalline or amorphous Cu-rich phase was formed. Increasing the deposition temperature, a fcc Cu phase was observed in addition to the crystalline TiN phase. The texture varied with the deposition temperature, and the grain size increased and the microstrain decreased with rising deposition temperature. The mechanical properties were measured by nanoindentation. For the nanocomposites Ti41N46Cu13, Ti43N46Cu11 and Ti43N49Cu8, hardness values of 25, 35 and 40 GPa, respectively, were measured.