Researchers develop new method for viewing fibre-reinforced composites
Researchers at the Paul Scherrer Institute PSI have improved a method for small-angle X-ray scattering (SAXS) to such an extent that it can now be used in the development or quality control of novel fibre-reinforced composites. This means that in the future, such materials can be investigated not only with X-rays from especially powerful sources such as the Swiss Light Source (SLS), but also with those from conventional X-ray tubes.
Novel fibre-reinforced composites are becoming increasingly important as stable and lightweight materials. One example of this type of composite is carbon fibre reinforced polymers (CFRP), which are used in aircraft construction or in the construction of Formula 1 racing cars and sports bicycles. The properties of these materials depend to a large extent on how the tiny fibres are aligned and how they are arranged and embedded in the surrounding material, influencing the mechanical, optical, or electromagnetic behaviour of the composites.
To investigate the fibre’s orientation in such composites, researchers must look inside them. One could use small-angle X-ray scattering (SAXS), exploiting the fact that X-rays are scattered when they penetrate matter. The resulting scattering pattern can then be used to obtain information about the interior of a sample and potentially the orientation of the fibres. However, the common SAXS methods have the disadvantage of being quite slow: It can take up to several hours to scan centimetre-sized specimens with the required resolution.
The new method works not only with X-rays from synchrotron facilities such as the Swiss Light Source SLS, but also with beams from conventional X-ray tubes. It is expected that this novel approach will find practical applications in medical devices and non-destructive testing as well as the area of homeland security Prof. Marco Stampanoni
Researchers at the Paul Scherrer Institute PSI and ETH Zurich, together with colleagues from EPF Lausanne and the Danish spin-off company Xnovo Technology, have now succeeded in further developing the technology for practical applications. As proof of principle, the researchers used the new method to display fibres’ orientation in a carbon fibre ribbon during the knotting process. They acquired time-resolved X-ray projections at a rate of 25 images per second over a period of 11 seconds.