Graphitization processes in wear tracks of Bi-layer carbon coating deposited by PVD-HiPIMS technique. (December 2020)

• Record Type: Journal Article
• Authors: Rivera-Tello, César Daniel; Flores-Ruiz, Francisco Javier; Flores-Jiménez, M.; Perez-Alvarez, J.; Jiménez, O.; Flores, M.
• Is Part Of: Materials today communications. Volume 25(2020)
• Publication Date: 2020-12
• Subjects: Graphitization -- Raman-analysis -- PVD-HiPIMS -- Friction-Coefficient; Materials science -- Periodicals; 620.11
• DOI: 10.1016/j.mtcomm.2020.101597
• Languages: English
• ISSNs: 2352-4928

Abstract

Abstract: This paper focus on a statistical Raman analysis to study the graphitization processes produced during a reciprocating tribological test on a design free hydrogen Bi-layer carbon coating deposited by PVD-HiPIMS. The design consists of a first layer L with a low sp 3 content to reduce stresses and improve adhesion to substrate, the second layer H has a high sp 3 content to increase the hardness and produce a smooth surface. The thickness and sp 3 ratios H / L were fixed at 2 by monitoring the HiPIMS discharge current. Images of the cross section verify a different growth mechanism for each layer. The tribological tests against alumina ball showed a coefficient of friction lower than 0.2 for applied loads in the range 0.75–1.50 N. Statistical Raman analysis revealed that as the tribo-test progress, the more sensitive fitting parameter in the Raman spectra was the G position followed of the coupling coefficient. Such parameters showed absence of graphitization at low load, and partial graphitization as the loads increase. All loads produced adhesive wear on the coating.