Evaluation of crack propagation in high-concentration Al-Mg-Si alloys using synchrotron X-ray imaging

Dynamic fracture behavior of Al-Mg-Si-based alloys was monitored through synchrotron X-ray computed microtomography and X-ray high-speed radiography during the tensile test. We have succeeded in measuring the internal crack propagation rate by X-ray radiography with high-speed microscopy. It was revealed that the internal crack propagation rate was much higher than the surface crack propagation in the Al-Mg-Si-based alloys containing a high amount of impurity elements. Ductility was changed according to the difference in second-phase particles contained in the Al-Mg-Si-based alloys. It was also shown that hydrogen atoms contained in the Al-Mg-Si alloys were released in the progress of cracks and fractures.