Microstructure evolution of Ti-(44-50)Al alloys during directional peritectic solidification

Using the thermodynamic model of TiAl binary system, part of phase diagram of Ti-(44-50) Al around the peritectic reaction was calculated and the solidus and liquidus of primary phase β and peritectic phase α were determined and the parameters used for interface response function were obtained. The interface temperatures of primary phase β and peritectic phase α were calculated for different growth conditions. According to the criterion of the maximum growth temperature, the phase selection and microstructure evolution of Ti-(44-50) Al were theoretically studied and a microstructure-selection map of TiAl stable state solidification as a function of the melt composition and the G/v ratio was constructed.