Research on the SR-CT technique in microstructures testing during dynamic processes

Synchrotron Radiation X-ray Computerized Topography (SR-CT) is an advanced technique, which is a unique combination of synchrotron radiation and computerized topography technique. Different from other conventional materials testing instruments, SR-CT technique has its advantages, such as non-destructive and real-time, etc. Therefore, it may be a powerful materials testing method in dynamic processes. However, there are also some actual problems. The high quality of the reconstructed images needs larger number of projections and much projection collecting time, but it is not allowed in dynamic processes because of sample evolution. Moreover, the noise in the projection images and some other factors reduced the reconstruction quality. The purpose of this work is to apply SR-CT technique in dynamic processes. A numerical simulation, including a generalized noise model considered the real situation of SR-CT experiment, different from the previous work, of SR-CT experiment was performed in order to carry out a quantitative evaluation on actual SR-CT experiment. A kind of iteration method was proposed to improve the quality of reconstructed images. The quality of reconstructed images was evaluated by three image evaluation parameters. The result shows that all three image evaluation parameters have obvious improvement by iteration method. Images from real SR-CT experiment were treated by iteration method to verify the effectiveness of iteration method, and high quality images can be obtained. The iteration method is appropriate and can be applied in the SR-CT experiment in microstructures testing during dynamic processes.