Study on hydrogen in aluminum ingots solidified under high pressure

Abstract

In order to study the effect of the pressure during solidification on hydrogen in aluminum ingots, aluminum melted in the hydrogen atmosphere was solidified under various pressures.
The results obtained are as follows:
(1) Macroscopic defects of aluminum ingots containing hydrogen decreased as pressure increased and almost disappeared at the pressure of 500 kg/cm².
(2) Densities of aluminum ingots containing hydrogen increased with an increase of the pressure. However, when the pressure was larger than 500 kg/cm², the increase of the densities was not observed. The higher the pressure, the more uniform density was attained through the whole ingot.
(3) It was found that there was a correlation between blister formation and pressure. From this, it was inferred that the experimental equation of Eichenauer and Pebler was useful to evaluate the hydrogen solubility in solid aluminum under high pressure.