Lamellar orientation control of TiAl alloys under high temperature gradient with a Ti–43Al–3Si seed

Microstructure evolution of directionally solidified Ti–46Al–0.5W–0.5Si alloy

“…Of the many microstructures that can be formed in TiAl-based alloys, the fully lamellar microstructure consisting of g-phase (TiAl) and a 2 -phase (Ti 3 Al) displays a good combination of room temperature toughness and elevated temperature strength [5]. However, initial application of TiAl alloys is limited to major obstacles such as low room-temperature ductility, the difficulty in processing then to fabricate a component and poor oxidation resistance above 800 1C [1][2][3][4]6]. Recent researches show that TiAl-based alloys with aligned lamellar orientation have a good combination of strength and ductility in a wide range of temperature [5,[7][8][9][10].…”

Crystal orientation control in TiAl–Nb alloys through a double directional solidification process

“…The directional solidification (DS) technique was widely applied to control lamellar microstructures consisting of TiAl (γ phase) and Ti 3 Al (α 2 phase) in TiAl-based alloys [1,2]. The DS alloys with the well-aligned lamellar microstructures exhibit a good combination of room temperature strength, plasticity and high temperature creep resistance in the axial direction [3].…”

Lamellar orientations and growth directions of β dendrites in directionally solidified Ti–47Al–2Cr–2Nb alloy

“…Research on polysynthetically twinned crystals of TiAl alloys shows that the best combination of strength and ductility can be achieved when lamellar boundaries are parallel to the tensile axis [4][5][6]. Thus, lamellar orientation controlling has been investigated during directionally solidified (DS) process, either by seeding of a phase [6][7][8][9][10][11] or by modifying solidification process [12][13][14].…”