Micro-reinforced Polymer Composite Materials Studied by Correlative X-ray Imaging

Three-dimensional insights into the microstructure of composite materials are vital for enhancing their performance under operational conditions. Phase-sensitive methods can offer supplementary data, especially for materials with low absorption, compared to standard absorption-based techniques. This work presents the correlative X-ray imaging and computed tomography results of polymer composites reinforced with glass fibers using an inverted Hartmann mask. This method identified areas with enhanced refraction and scattering due to glass fibers and discriminated signals based on their orientation, offering an advantage in evaluating anisotropic materials. The simplicity of the setup, adding the inverted Hartmann mask, makes integration feasible in commercial CT scanners and existing radiography laboratories, enabling simultaneous phase, scattering, and absorption information extraction. Our approach, which combines refraction and scattering with absorption signals, exposes intricate structures beyond the usual spatial resolution threshold. Despite the distinct absorption coefficients of air, polymer-based, and glass fibers, the inverted Hartmann mask is crucial for examining similar absorption composites and low-absorbing materials. This research offers profound insights into the microstructures of fiber-reinforced polymer composites, laying the groundwork for studies of nanostructured functional composite materials.