Microstructure, wear and corrosion behavior of nano-CeO2 doped diamond-like carbon (DLC) composite films

Diamond-like carbon (DLC) composite films doped with ceria were synthesized on LY-12 aluminum alloys by electrodeposition. The effects of ceria concentration on the microstructure, microhardness, wear and corrosion behavior of the composite film were investigated via Raman spectroscopy, X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), micro-Vickers tester, friction and wear tester and electrochemical workstation. Meanwhile, the growth mechanism of the films was explored. Results proclaimed that the loose honeycomb structure of the films was replaced by a compact granular structure as the ceria concentration increased to 1.16 ×10−3 mol/L. Raman spectra showed the typical amorphous characteristics of DLC film. The intensity ratio of G-line and D-line (ID/IG) diminished from 0.59 to 0.47, the G-line shifted to the lower frequency and the GFWHM increased, demonstrating that the CeO2/DLC composite film deposited at optimal ceria contains the higher sp3-C content. XPS analysis revealed that the binding mode of ceria is physically doped. Furthermore, the CeO2/DLC composite film exhibits superior anti-wear and anti-corrosion ability, which is primarily due to the compact structure and high microhardness. Double Ni-Cu interlayer are prepared and CeO2 nanoparticles were successfully encapsulated in diamond-like carbon (DLC) films on LY-12 aluminum alloy substrates by electrodeposition.