Structure and mechanical properties of carbon fibres:: a review of recent microbeam diffraction studies with synchrotron radiation

Hard X- ray beams with beam sizes in the sub- micrometre range are frequently available at third- generation synchrotron radiation sources, enabling new insights into the structure of materials at different levels of hierarchy by applying novel techniques such as scanning microbeam diffraction or scanning small- angle scattering. The high brilliance of the radiation from wiggler and undulator sources allows in situ experiments such as mechanical testing of single fibres to be performed, and even the combination of microbeam scanning with in situ testing is feasible. Three different experiments on single carbon fibres are presented: an in situ tensile test using a 10 mu m collimated beam, a scanning experiment applying a 3 mu m beam from a tapered glass capillary, and a scanning experiment with simultaneous in situ bending with a 0.1 mu m beam provided by a waveguide structure.