Phase-contrast and dark-field imaging for the inspection of resin-rich areas and fiber orientation in non-crimp vacuum infusion carbon-fiber-reinforced polymers

0540851 - ÚTAM 2022 RIV US eng J - Journal Article
Glinz, J. - Šleichrt, J. - Kytýř, Daniel - Ayalur-Karunakaran, S. - Zabler, S. - Kastner, J. - Senck, S.
Phase-contrast and dark-field imaging for the inspection of resin-rich areas and fiber orientation in non-crimp vacuum infusion carbon-fiber-reinforced polymers.
Journal of Materials Science. Roč. 56, č. 16 (2021), s. 9712-9727. ISSN 0022-2461. E-ISSN 1573-4803
R&D Projects: GA MŠMT(CZ) EF16_019/0000766
Institutional support: RVO:68378297
Keywords : carbon fiber reinforced plastics * computerized tomography * graphite fibers
OECD category: Composites (including laminates, reinforced plastics, cermets, combined natural and synthetic fibre fabrics
Impact factor: 4.682, year: 2021
Method of publishing: Open access
https://doi.org/10.1007/s10853-021-05907-0

In this work, we present a multimodal approach to three-dimensionally quantify and visualize fiber orientation and resin-rich areas in carbon-fiber-reinforced polymers manufactured by vacuum infusion. Three complementary image modalities were acquired by Talbot–Lau grating interferometer (TLGI) X-ray microcomputed tomography (XCT). Compared to absorption contrast (AC), TLGI-XCT provides enhanced contrast between polymer matrix and carbon fibers at lower spatial resolutions in the form of differential phase contrast (DPC) and dark-field contrast (DFC). Consequently, relatively thin layers of resin, effectively indiscernible from image noise in AC data, are distinguishable. In addition to the assessment of fiber orientation, the combination of DPC and DFC facilitates the quantification of resin-rich areas, e.g., in gaps between fiber layers or at binder yarn collimation sites. We found that resin-rich areas between fiber layers are predominantly developed in regions characterized by a pronounced curvature. In contrast, in-layer resin-rich areas are mainly caused by the collimation of fibers by binder yarn. Furthermore, void volume around two adjacent 90˚-oriented fiber layers is increased by roughly 20% compared to a random distribution over the whole specimen.
Permanent Link: http://hdl.handle.net/11104/0318749