In-situ observation of hydrogen microporosity nucleation and growth during superheating of Al–Li alloy

The evolution of hydrogen microporosity in Al–Li alloy during superheating has been observed using synchrotron X-ray radiography. The growth kinetics of microporosity are investigated to elucidate the evolution mechanism. The results demonstrate that microporosity is susceptible to migration, merging, and dissolution during its growth. In addition, microporosity diameters conform to a Gaussian distribution during the initial stage of superheating. However, the evolution of group microporosity is controlled by Lifshitz-Slyozov-Wagner (LSW) diffusion during the final stage. The nucleation and growth of microporosity during superheating are primarily influenced by the competition between hydrogen diffusion and dissolution.