LAUSR

Abstract Hydrogen is the only gas able to dissolve in aluminum. The solubility S of hydrogen in Al obeys the Sieverts' law and S is much larger in the liquid phase (above 660.4 °C) than in the solid one. This might lead to the formation of porosity during aluminum casting. In the present work, the ternary system Al–H– RE ( RE  = Er, La, Y) is investigated. The equilibria between the different phases are determined in the presence of liquid Al, RE and H 2 gas by both experimental measurements and phase diagram calculations. The possible formation of metallic hydrides and the change in the hydrogen solubility S are discussed regarding pressure and temperature determining the thermodynamics of the system.