This paper presents a Raman spectroscopy study of the influence of methane flow on the micro-tribological behavior of diamond-like carbon coatings deposited with an industrial plasma-enhanced chemical vapor deposition system. Results have shown a direct relationship between the methane flow and thickness of the coatings. The analysis of the Raman spectra and deposition parameters allowed establishing the influence of H content with the methane flow, the disorder level and estimation of the sp3 fraction on the carbon coatings. The micro-tribology tests showed a strong dependence of the wear resistance and hardness with Raman parameters. The coating deposited at 72-sccm methane flow presented a thickness of 1.7 μm and a sp3 fraction of 0.33. This sp3 fraction gave rise to a hardness of 24 GPa and an excellent wear resistance of 3.3 × 10–6 mm3 N−1 mm−1 for this DLC coating. Wear tests showed a swelling in the wear profiles on this coating, which was associated with the occurrence of a re-hybridization process.

    Abstract
    1 Introduction
    2 Materials and methods
    3 Results and discussion
        3.1 Morphological and Raman characterization
        3.2 Micro-tribology
    4 Conclusions
    Acknowledgements 
    References

• César Daniel Rivera‑Tello(Departamento de Ingeniería Mecánica Eléctrica, CUCEI, Universidad de Guadalajara)
• Francisco Javier Flores‑Ruiz(CONACYT‑Instituto de Física, Benemérita Universidad Autónoma de Puebla)
• M. Flores(Departamento de Ingeniería de Proyectos, CUCEI, Universidad de Guadalajara)
• O. Jimenez(Departamento de Ingeniería de Proyectos, CUCEI, Universidad de Guadalajara)
• I. Farías(Departamento de Ingeniería de Proyectos, CUCEI, Universidad de Guadalajara)
• J. Oseguera‑Peña(Termoinnova S.A. de C. V. Boulevard Central, 5000 int. 14, Parque industrial Atitalaquia, Tecnológico de Monterrey-CEM, Carretera al Lago de Guadalupe km 3.5)