Influence of Atomic and Molecular Hydrogen in Silumins Melts on Their Mechanical Properties

We study the influence of gas porosity caused by the presence of dissolved hydrogen on the mechanical properties of Al–Si alloys. The results are obtained by testing cast samples with identical contents of hydrogen and a given (atomic or molecular) form of hydrogen inclusions. The dependence of the mechanical properties of alloys on the density index is statistically established. It is shown that if the density index increases and hydrogen is released in the atomic form, the mechanical properties remain practically unchanged, whereas the presence of hydrogen in the molecular form in silumin deteriorates the mechanical properties of the metal.