Activity of magnesium in liquid Ag–Mg alloys

Activity measurements of magnesium in liquid Ag–Mg solutions were carried out at 1573, 1673, 1773 and 1823 K using two different techniques. While most measurements were carried out using the vapor pressure method at 1573 and 1673 K, a number of measurements were made at 1773 and 1873 K using the gas equilibration technique. The latter method was used mostly for obtaining Ag–Mg solution at very low Mg contents. It was found that magnesium had a negative deviation from ideality in Ag–Mg solutions. The excess Gibbs energy of Ag–Mg solutions seemed to have a quite weak temperature dependency in the temperature region studied. The excess Gibbs energy of Ag–Mg solution can be described as; Δ G M g − A g X S = X M g X A g ( − 66583 + 23970 ( X A g – X M g ) )  J/mole  between 1573 and 1823 K