Cooper-Carbon Nanostructured Composite Coatings with Controlled Structure

Abstract

Samples of the Cu-C composite coatings were produced by high-speed ion-plasma magnetron sputtering (HiPMS) with mosaic target (MT). Nanostructure, roughness, mechanical properties as well as electric properties of coatings depend on carbon-cooper ratio. So 10% - 15% cooper con centration (atomic) results in to dry friction coefficient decrease up to 0.1 and wear resistance increase up to 10-17 m3/N·m. The HiPMS method allowed us to effectively sputter very different materials like carbon and cooper at the same velocity with required proportion. At the same time, one could obtain a uniform mixture of ingredients on the atomic level. The coating corresponds to a mixture of nano-sized phases of carbon and cooper. Crystalline dispersion of samples depends on carbon concentration. The obtained products are characterized by XRD, UV (257 nm) and visible (514 nm) Raman spectroscopy. The morphologies are studied with TEM and AFM. Mechanical properties were investigated with friction coefficient and micro hardness tests. There was no chemical interaction during Cu-C precipitation on hot substrate (625 - 725 K). The mechanical properties can be explained by free electrons capture with carbon nanostructures and space charge formation.