Characteristics of phase transformations of
Ti-23Al-25Nb alloy and Ti-23Al-25Nb-0.36Y alloy were analyzed by DTA. Heat treatment
conditions of these alloys were worked out according to the DTA results. The microstructures and phase analysis of these alloys were analyzed by means of SEM and XRD. The existence state of Y in the original
microstructure was determined by means of TEM. Room temperature compression tests were carried out on the Instron-5569 machine. Research results show that Y in the original structure exists in the form of Y2O3, but it does not change the phase transformation temperature of
Ti-23Al-25Nb alloy. After quenching at 1320℃, the grain sizes of B2 phase in Ti-23Al-25Nb-0.36Y alloy are coarser than those in Ti-23Al-25Nb alloy. With decreasing of quenching temperature, the amount of O phase increases, and its plates are thinned and more cluttered. Adding of Y increases the strength of the alloy, which is attributed to the dispersion strengthening of second phase particles of Y2O3.