Few layer graphene to reduce wear and friction on sliding steel surfaces

We report that solution-processed graphene layers reduce friction and wear on sliding steel surfaces in air (relative humidity, 30%). In tests with sliding steel surfaces, small amounts of graphene-containing ethanol solution decreased wear by almost 4 orders of magnitude and friction coefficients by a factor of 6. A possible explanation for these results is that the graphene layers act as a two-dimensional nanomaterial and form a conformal protective coating on the sliding contact interfaces, and these factors facilitate shear and slow down the tribo-corrosion, thus drastically reducing the wear. (C) 2012 Elsevier Ltd. All rights reserved.