Evolution of Microstructures and Properties of Ti-44Al-6V-3Nb-0.3Y Alloy after Forging and Rolling

Generally, beta gamma -TiAl alloys possess excellent hot deformability and good mechanical properties. In this paper, the evolution of microstructures and tensile properties of Ti-44Al-6V-3Nb-0.3Y (at.%) alloy after hot forging and rolling were investigated systematically. SEM results indicated that the cast microstructure of current TiAl alloy was completely broken down and refined by forging and rolling. By SEM and TEM measurements, the detailed microstructures and phase composition in the as-forged and as-rolled conditions were characterized and compared. Fully lamellar microstructures of the deformed alloy were obtained by heat treatment of 1330 degree C/1h/FC+900 degree C/10h; Additionally, to assess the effect of microstructure variation on mechanical properties, tensile properties were measured at room temperature and 700 degree C. It is an extremely effective mean to optimize the microstructures and enhance the mechanical properties of TiAl alloy by hot forging and rolling.