Influence of intermetallic particles on the initiation and growth behavior of hydrogen micropores during high-temperature exposure in Al-Zn-Mg-Cu aluminum alloys

Abstract X-ray tomography is employed to observe the effects of intermetallic compound particles on the nucleation and growth of hydrogen micropores at high temperatures in Al-Zn-Mg-Cu aluminum alloys. Hydrogen micropores are heterogeneously nucleated on particles during exposure at 748 K. Growth and coalescence of the hydrogen micropores are observed with increasing exposure time. Interactions between hydrogen micropores and particles have a significant influence on the growth and coalescence of hydrogen micro pores. The growth speed of hydrogen micropores, nucleated on spherical, small particles is faster than those on other nucleation sites.