Synthesis of Cu doped TiN composite films deposited by pulsed bias arc ion plating

The Ti-Cu-N films with different compositions were deposited by pulsed bias arc ion plating. The effect of Cu on the structure and mechanical properties of these films is investigated by means of electron probe micro-analyzer (EPMA), grazing incident X-ray diffraction (GIXRD), X-ray photoelectron spectroscopy (XPS), field emission scanning electron spectroscopy (FE-SEM) and nanoindentation, respectively. It is shown that the Ti-Cu-N film with low Cu content presents a pronounced columnar growth. The hardness enhancement in Ti-Cu-N films from 23 GPa for pure TiN to maximum of 37 GPa with 0.6 at.% Cu content might be correlated with the change of nanocomposite structure. Meanwhile, with further addition of Cu, the columnar structure is replaced by a dense globular structure, and the film hardness is greatly reduced due to excess soft metallic Cu. Therefore, pulsed bias arc ion plating as an effective tool can tailor the structure and mechanical properties of Ti-Cu-N composite films.