Graphene oxide in water lubrication on diamond-like carbon vs. stainless steel high-load contacts

• Graphene oxide improved water lubrication in DLC-stainless-steel high load contact.
• The friction coefficient decreased 57% compared to pure water.
• GO embedded on steel counter surfaces.

The friction and wear performance of 0–2 wt.% graphene oxide (GO) dispersions in water were studied on diamond-like carbon vs. stainless steel contact by a pin-on-disk tribometer. The wear surfaces were characterized using contact profilometry, X-ray spectroscopy, optical microscopy, scanning electron microscopy, energy dispersive spectroscopy, and Raman spectroscopy. The friction coefficient decreased 57% (from 0.14 to 0.06) compared to pure water, when 1 wt.% of GO and 10 N normal load were applied. A minimum wear for the counter ball was detected when pure water was used. GO additives reduced the corrosive effect on the counter ball. The main tribological mechanism of GO additives in water was observed to be the embedding of GO sheets on the counter ball surface forming a lubricating layer and binding water molecules into the contact.