Deposition of Ni-TiN nano-composite films by cathodic arc ion-plating

Thick composite films containing Ni and TiN were prepared by using the filtered cathodic are ion-plating method. In this study, Ni and Ti were simultaneously evaporated by vacuum are discharge in a nitrogen atmosphere. Since a magnetic field in a filtered are-evaporator transports only small size ionized particles to the substrate, macro-particles are eliminated from the film and a uniform fine structure can be obtained, It was observed by transmission electron microscopy (TEM) and X-ray diffraction analysis (XRD) that Ni and TiN particles with 5-10 nm diameter were deposited. Scanning electron microscopy (SEM), and energy dispersive X-ray analysis (EDX) were also used to investigate the morphology and the composition of films. Residual stresses were evaluated by measuring the bending of the substrate before and after the deposition. Hardness measurements were also carried out to investigate the mechanical properties of films. The hardness of the film increased with the increase in the TiN content of the film. When the Ni content was lower than 30 at%, the hardness of the film was nearly the same as TiN itself. The residual stresses of the Ni rich films were 0.05-0.5 GPa (tensile stresses) and those of the TIN rich films were -1--3 GPa (compressive stresses). Substrate bias voltage and N-2 pressure had a great effect on the residual stress. The compositionally graded multi-layered films (thickness of 350 mu m) were synthesized from these results.