On-the-fly fast X-ray tomography inspection of the quasi-brittle material three point bending test
Measurement and visualization of the fracture process zone (FPZ) in the silicate composites is essential for understanding how the crack is formed and how it is propagating through the material. Although several time-lapse radiography and tomography experiments during the three-point bending of silicate composites with conventional imaging techniques have been already realized, the crack initiation and propagation is so fast process, that it is very difficult to capture sufficient spatial information in the exact moment when this process is occurring. Nowadays progress in X-ray imaging instrumentation, especially single photon counting CdTe detectors with a fast parallel readout, allows speeding up the acquisition of the tomographic data while keeping the intrinsic resolution of tens of micrometers and high efficiency even for photons with higher energy. Tomography of relatively fast processes is becoming realistic even in laboratory conditions using commercially available microfocus X-ray tubes. As an example of such a fast tomography, results of “on-the-fly” series of tomographic experiments performed on the specimen subjected to continual three-point bending test is presented.