Wear-resistant metal-carbon composite coating

Carbon coatings containing a metallic component (zirconium, tantalum) were deposited with ion assistance on AISI M2 steel samples using a SVETLYACHOK source. The coatings were studied by Auger electron spectroscopy (AES), transmission electron microscopy (TEM), Raman spectroscopy (RS) and pin-on-disc tribological tests. The results have shown that the carbon coatings contain up to 20 at.% of the metallic component. These coatings have an amorphous structure with sp³-type bonds. The presence of the coating on the surface of AISI M2 steel reduces the friction coefficient by a factor of five under the tribological conditions investigated. It is found that the tribological properties of the coatings deposited with the assistance of metal ions are significantly better than those coatings deposited with assistance of carbon ions. The latter coatings had carbon atoms with mixed sp³-sp² bonds. The deposited composite carbon coatings are stable at a temperature of 100°C and allow a twofold improvement in the lifetime of fuel pump rods. (C) 2000 Elsevier Science S.A. All rights reserved.