In this study, we systematically investigated the effects of negative bias voltage on the composition, deposition efficiency, microstructure, and mechanical properties of multi-arc ion plated (MAIP) AlTiN films. The films were deposited on high-speed steel substrates by MAIP at various negative bias voltages. The results indicated that the Al content [Al/(Al+Ti) ratio] and the deposition efficiency were significantly altered by the application of negative bias voltages. X-ray photoelectron spectroscopy analysis showed that the AlTiN films were composed of TiN and Al-N bonds. The macroparticles (MPs) on the film surface decreased with increasing negative bias voltage. We also discussed the different types of MPs found on the films and their influence on the process of determining the hardness of the films. The microhardness of the films depends on the negative bias voltages. The films deposited at-250 V exhibited a maximum hardness of ~45 GPa. The adhesion and frictional tests revealed that the film deposited at-150 V demonstrated the highest cracking resistance, the best adhesion under a critical load of 78 N, highest adhesion strength, and the lowest and stablest coefficient of friction at 0.23.

Zn-Al film was prepared on biaxially oriented polypropylene (BOPP) substrate via vacuum thermal evaporation. The microstructure and its correlation with sheet resistance of Zn-Al film were explored systematically. The results showed that the macromorphology of Zn-Al film was closely related to the surface topography of BOPP substrate. XRD and SEM analysis indicated that Zn-Al film displayed a columnar and strong textured structure of Zn (002). TEM results revealed that the film thickness was in the range of 20-25 nm, of which amorphous alumina was identified on/at the surface and interface, while Zn and a small amount of ZnO were detected in the middle. The amorphous alumina on the film surface prevented the further oxidation of Zn, and therefore helped to improve the stability of sheet resistance of the film. Nevertheless, the insulative alumina significantly decreased the film conductivity, which deteriorated the current handling ability of metallized film capacitors.