Graphene-ceramic nanocomposites for tribological application in aqueous environments - GRACE

Ceramic materials like silicon carbides (SiC) are widely used in slide bearings and face seals as they provide a high wear resistance in aqueous media. Nevertheless, efforts are being made to keep energy losses caused by friction processes as low as possible and to increase the lifetime and durability of the tribologically loaded components. The addition of graphene into the SiC lattice is a promising approach to meet these requirements as this carbon modification strengthens the microstructure, chemically passivates the surface and decreases friction and wear.

Within the project GRACE, SiC-graphene-nanocomposites were produced and tested under water-lubricated conditions to assess their usability for technical applications. In addition, also silicon nitride-graphene nanocomposites were developed and assessed concerning their mechanical and tribological properties.

During the project, several goals could be achieved:

• Successful Development of innovative process routes to manufacture graphene dispersions and coat SiC particles with graphene
• Sintering, mechanical, microstructural and tribological characterization of SiC-and Si₃N₄-graphene-nanocomposites
  • Correlation of the graphene manufacturing process and graphene content with the mechanical, friction and wear behaviour
  • Evidence of the conditions and microstructures under which the best tribological results are achieved
  • Modelling of the wear mechanisms and tribo-chemical processes which determine the friction behaviour
• Atomistic simulation of the tribological contact on graphene layers on the SiC surfaces revealed tribological mechanisms to explain the friction behaviour on the macro-scale.
• Manufacture of seals with SiC-graphene-nanocomposites and demonstration of the results under operation conditions.

The results were presented and discussed at various conferences and published in peer-reviewed journals. In addition, a patent application concerning the coating of SiC with graphene was filed by EagleBurgmann Germany.

Project Details