Synthesis and Tribology of Micro-Carbon Sphere Additives for Enhanced Lubrication

Abstract

Poor or inefficient lubrication often gives rise to high friction and wear losses in machine components, which adversely affect their performance, efficiency, and durability. Many approaches are being explored to enhance the antifriction and antiwear properties of sliding machine components. In this study, the antifriction and antiwear properties of carbon spheres, synthesized from plastic waste by an autogenic process, were investigated as an additive to a poly-alpha-olefin (PAO-4 grade) oil. When dispersed at 1 wt% concentration, the carbon spheres reduced both friction and wear under boundary-lubricated sliding conditions. In particular, the reduction in wear was quite dramatic and appeared to be enabled by the formation of a fairly thick (≈200 nm) carbon-rich boundary film, the formation of which is attributed to tribochemical interactions between the carbon particles and sliding contact surfaces.

KEY WORDS:

• Carbon
• Spheres
• Additive
• Lubricant
• Tribology
• Tribofilm

Additional information

Funding

This research was supported by the U.S. Department of Energy (DOE). Use of DOE's facilities at the Center for Nanoscale Materials and Electron Microscopy Center at Argonne National Laboratory, both of which are supported by the Office of Science, and the XPS, AES, FIB, and TEM facilities at the Frederick Seitz Materials Research Laboratory, University of Illinois at Urbana–Champaign, is gratefully acknowledged. The submitted manuscript has been created by UChicago Argonne, LLC, Operator of Argonne National Laboratory (“Argonne”).

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