X-ray spectroscopy and tomography for improving metal-graphene composite materials

Purpose and goal:

This project was a collaboration with Uppsala University and Graphmatech AB. Graphmatech produces metal-graphene composites for e.g. improved electrical contacts and corrosion barriers.

A major aim with this project was to evaluate if the synchrotron-based techniques ARPES, HAXPES and X-ray tomography are suitable for continuous product development by providing answers about metal-graphene interaction in composite materials as well as the quality of 3D-printed parts of these composite materials.

Expected results and effects:

Of the three tested analysis methods have HAXPES and X-ray tomography great potential to give deeper understanding about the properties of metal-graphene composite materials. HAXPES measurements can clearly indicate carbide formation and this method will be further explored. X-ray tomography gave a clear view of voids down to 10um in size and their spreading in 3 dimensions in a non-destructive way.

To study electronic doping using nano-ARPES turned out too time consuming to become a standard analysis method. Approach and implementation:

Carbide formation was studied with HAXPES on AM-printed and polished pieces (8x8x5mm) of Cu and steel (316L) with and without graphene, using the SPLINE beamline at ESRF in France using a photon energy of 9 keV.

A printed piece shaped to a thin rod (4mm diameter, 50 mm long) were studied using x-ray tomography in transmission mode at the P21.2 beamline of Petra III, Germany. Finally, a single graphene attached to a Cu particle flake was studied using nano-ARPES at the ANTARES beamline of Soleil, France, a copper(Cu)-graphene powder pressed into Au foil was used as sample.