Abstract:A new model was established to calculate the real vapor pressure of the Al element in the molten Ti-xAl (x=25～50, mole fraction, %) alloy. The effects of the holding time, chamber pressure, mole fraction of Al and melting temperature on the real vapor pressure of Al element in the vacuum chamber were analyzed. Because of the impeding effect of the real vapor pressure on the evaporation loss rate, within a short time (less than 10s), the real vapor pressure tends to a constant value. When the chamber pressure is less than the saturated vapor pressure of the Al component, the real vapor pressure of Al is equal to the chamber pressure. While when the chamber pressure is larger than the saturated vapor pressure, the real vapor pressure is equal to the saturated vapor pressure of the Al element of the same condition.

Key words: real vapor pressure; Al element; ISM process; Ti-xAl melt