X-ray tomo-ptychography of single micrometric carbon and basalt fibres

Carbon fibre-based composite materials are essential for emissions reduction in transportation. However, the physical properties of their main component, i.e. the micro-size carbon fibres, are still poorly documented because of experimental difficulties. Such material is however known for presenting high anisotropy between off- and on-axis properties. Here we have used Ptychography X-ray Computed Tomography to probe quantitatively the bulk electronic density and the morphology of micrometric carbon and basalt fibres. The carbon fibre exhibits a density variation as function of its radius, with a maximum at its center and a minimum around half of the radius, while the basalt fibre is homogeneous. Morphology is investigated at the fibre scale to quantify its deviations from a perfect cylinder and at the nanoscale to evaluate the texture of the surface. Resolutions are around 200 nm. This pioneering work should open new understandings and bulk or surface experimentations on single micron-size fibres at the nanoscale.