Compliant and Hard Cu(Ni)-C Nanocomposite Coatings

Abstract

Copper-Nickel-Carbon nanocomposite coatings are synthesized by the sequential sputter deposition of carbon (C) and a copper-nickel (Cu 1-x Ni x ) alloy. A distinct transition occurs as the Ni content (x) is increased from 0 to 1.00 during the Cu 1-x Ni x alloy deposition. The coating morphology changes from a dispersion of metallic Cu-particles in a C matrix to a well-defined nanolaminate structure. Between these morphological forms, a new prototype nanocomposite is produced at a Ni concentration (x) of 0.1-0.4 with the appearance of an interpenetrating matrix structure of C and Cu(Ni). This morphological structure has both a high 24-27 GPa hardness (H) and a low elastic modulus (E) of 144-169 GPa that results in a record high values of H/E at 1/6 and a H 3 /E 2 at 0.67-0.69 GPa in a novel compliant and hard coating.