Abstract:Based on the coexistence theory of metal melt involving compound formation and Butler’s equation, a new model was proposed for the calculation of surface tension of alloy melt. This model established a specific correlation between the surface tension and mass action concentrations(activities) of bulk melt and surface melt on the basis of surface and bulk melt structures. It was shown that the calculated surface tensions for Fe-Si, Fe-Al alloy melt are in good agreement with the measured results. Furthermore, iso-surface tension lines for Fe-Si-Al alloy melt were also calculated.

Key words: alloy melt　surface tension　activity　mass action concentration