Nanomechanical properties through nanoindentation method of amorphous carbon and carbon nitride films synthesized by shielded arc ion plating

Amorphous carbon (a-C) and carbon nitride (a-CNx) films were deposited by means of shielded arc ion plating (SAIP) with an arc current of 60 A operated in a gas pressure of 1 Pa. A bias voltage in the range from 0 to −500 V was applied to a substrate during film deposition. Nanomechanical properties of the films were measured by a nanoindentation interfaced with an atomic force microscopy (AFM) using a diamond tip. The nanoindentation was also applied to evaluate wear resistant behavior of the films in nm scale. The a-C film prepared at a substrate bias voltage (Vb) of −100 V was hardest in the present study so as to show a hardness of 43±3 GPa. This a-C film was most wear resistant as well. The a-CNx film prepared at Vb of −300 V possessed the maximum hardness of 14±1 GPa among the prepared a-CNx films. Independently of Vb, all of the a-CNx films showed better wear-resistance characteristics than sapphire and quartz. Although the wear-resistance of the films was not directly correlated to its hardness, elastic modulus, elastic recovery, plastic deformation energy, these properties were certainly govern the wear-resistance of the film.