Assessment of the tribological performance of materials under high pressure hydrogen gas

The development of hydrogen-based technologies faces several material-related challenges. Beyond the critical issue of producing green hydrogen at a competitive cost, the durability of materials is a key factor in realizing hydrogen’s potential as a clean energy carrier. In this context, tribological challenges are emerging in hydrogen compression and distribution systems. Mechanical components in these systems must withstand high hydrogen pressures—often exceeding 700 bar—and exhibit minimal wear and friction. These demanding conditions highlight the need for ongoing research into advanced materials and protective coatings to ensure long-term reliability and performance.

To address these challenges, materials and coatings were evaluated using a ball-on-flat contact configuration on a high-pressure hydrogen tribometer. The tests were conducted under reciprocating sliding motion at a maximum contact pressure of 975 MPa in hydrogen environments of up to 100 bar. Hydrogenated amorphous carbon (a-C:H DLC) coatings were applied to the ball and tested against steel flats, with results compared to uncoated steel/steel contacts. The influence of the surface roughness of the steel flats was also investigated. The use of DLC coatings on the ball significantly reduced both friction and wear, demonstrating their potential for improving the tribological performance of components in hydrogen systems especially in the energy and the mobility applications fields.