On the heterogeneous nucleation pressure for hydrogen pores in liquid aluminium

Heterogeneous nucleation based on the spherical cap model has been used in this study to evaluate nucleation pressure and the number of hydrogen atoms necessary for nucleation. Calculations have shown that the minimum heterogeneous nucleation pressure that can be achieved is in the order of 1 GPa, which is four orders of magnitude larger than the values assumed in the literature. Implications of the results are discussed.