Friction and Wear Reduction of Tungsten Carbide and Titanium Alloy Contacts via Graphene Nanolubricant

The tribological behavior of graphene as an additive in a water-based nanofluid lubricant was investigated using pin-on-disk tests on titanium alloy (Ti-6Al-4V) and cemented tungsten carbide (WC-Co) contacts. The effect of graphene concentration and surface roughness was investigated. A non-monotonic trend of friction and wear with increasing concentration was observed. An optimal graphene concentration of 0.10 wt.% was found to provide the lowest friction and wear at different surface roughnesses, with the friction, specific wear rate of the sample surface, and tip wear reduced by 29%, 37%, and 95%, respectively. The friction reduction and anti-wear performance of the nanofluids increased as the sample surface roughness increased. The non-monotonic friction and wear trends can be explained by the agglomeration of graphene around the contact zone, where too small a graphene concentration does not provide enough lubrication and too high a concentration prevents sliding owing to a large amount of agglomeration particles at the contact. The superior friction and wear performance of the graphene nanolubricants demonstrate its potential in minimum quantity lubrication (MQL) and other applications.

Automated summary

Graphene as an additive in a water-based nanofluid lubricant demonstrates superior friction and wear performance, reducing friction coefficient and wear rate. The effect of graphene concentration on friction and wear exhibits a non-monotonic trend. An optimal concentration of 0.10 wt.% is found at different surface roughnesses.