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

Jonathan Glinz, Jan Šleichrt, Daniel Kytýř, Santhosh Ayalur-Karunakaran, Simon Zabler, Johann Kastner & Sascha Senck - Journal of Materials Science

The high strength at moderate weight in combination with superior corrosion and fatigue properties makes carbon-fiber-reinforced polymer (CFRP) an attractive material for lightweight applications in aerospace. Nonetheless, besides several benefits, CFRP components also bear significant risks like a low resistance to impact damage. […] 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).

How Amira-Avizo Software is used

Image fusion of several DFC layer data was performed in Avizo 2019.4 (Thermo Fisher Scientific Inc., USA). Prior to the fusion, non-local means (NLM) filtering with a search window of 10 pixels, a local neighborhood value of 5 pixels and similarity value 0.3 was applied in order to reduce the influence of image noise and artifacts among the datasets. Parameters of the NLM filter were determined empirically to reduce image noise without losing information on fiber layers.