Abstract
The microstructure of carbon/carbon composites obtained by isothermal, isobaric chemical vapor infiltration (CVI) of carbon fiber preforms consisting of aligned fiber bundles separated by fiber fleeces was studied comparatively by polarized light microscopy (PLM), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) combined with selected area electron diffraction (SAED). Deposition rate as well as matrix microstructure do not differ in the aligned fiber bundles and fiber fleeces exhibiting different local surface area/volume ratios. The matrices which are homogeneously textured according to PLM exhibit pronounced spatial texture gradients at the sub-μm-scale if investigated by SAED. The texture gradients appear to be independent on the infiltration time, distance between fibers but evidently depend on the total methane pressure. TEM and SEM observations show a thin high-textured layer between the fiber and the medium-textured transitional layer below the high-textured matrix layer containing columnar grains. This thin layer replicates the surface unevenness of the fiber surface while it is absent at the initial carbon fiber surface before infiltration.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
