Microstructure, mechanical properties and corrosion behavior of Ce doped TiN films

The Ce doped TiN (Ti-Ce-N) films with different Ce contents (1.91, 5.75, 7.95, 9.16, 14.19 at.%) were prepared by reactive magnetron co-sputtering method using Ti and Ce target as the Ti and Ce supplier, respectively. Microstructural observation results indicate that the Ti-Ce-N films with Ce contents from 1.91 to 9.16 at.% exhibit a single face centered cubic structure and the film with Ce content of 14.19 at.% transforms into an amorphous structure. The substitution of Ce atoms for Ti atoms in Ti-Ce-N films leads to the increase of cell volume and grain refinement. Measurement results of mechanical properties show that the hardness and elastic modulus of Ti-Ce-N films are increased as the increase of Ce content from 1.91 to 9.16 at.% because of solution strengthening and fine-grained strengthening. Polarization curves and electrochemical impedance spectroscopy indicate that the corrosion resistances of TiN films are improved obviously with Ce doping contents of 9.16 at.% and 14.19 at.% compared with undoped TiN film.