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The cast ingots of Ti-46Al-6Nb-0.25Si-0.2B and Ti-46Al-6Nb-0.5W-0.25Si-0.2B(at%) were made by induction skull melting(ISM) technique.A series of heat treatments(HTs) were conducted to research the microstructure evolution of both alloys.Microstructure and tensile property were examined by scanning electron microscope(SEM),X-ray diffraction(XRD),transmission electron microscope(TEM),and tensile testing machine.The results show that microsegregation(liquid segregation and solid segregation) is exacerbated by the addition of0.5 at%W;the addition of Nb,W in TiAl alloy makes the phase transition difficultly take place;then,the microstructures and tensile properties of both alloys are improved after certain HT processes;finally,the thicknesses of the γ/α_2 lamellae after a certain HT process are significantly affected by the number of residual γ phases before the furnace-cooling moment.
The cast ingots of Ti-46Al-6Nb-0.25Si-0.2B and Ti-46Al-6Nb-0.5W-0.25Si-0.2B (at%) were made by induction skull melting (ISM) technique. (HTs) were conducted to research the microstructure evolution of both alloys. Microstructure and tensile properties were examined by scanning electron microscope (SEM), X-ray diffraction (XRD), transmission electron microscope (TEM) show that microsegregation (liquid segregation and solid segregation) is exacerbated by the addition of 0.5 at% W; the addition of Nb, W in TiAl alloys makes the phase transition difficultly take place; then, the microstructures and tensile properties of both alloys are improved after certain HT processes; finally, the thicknesses of the γ / α_2 lamellae after a certain HT process are significantly affected by the number of residual γ phases before the furnace-cooling moment.