EFFECTS OF TEMPERATURE GRADIENT ON LAMELLAR ORIENTATIONS OF DIRECTIONAL SOLIDIFIED TiAl--BASED ALLOY

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

“…Jung et al [44] have indicated that the lamellar orientation in the DS Ti-47Al-2W (at%) alloy inclined at angles of 60-901 to growth direction at the growth rate of 90 mm/h. Xiao et al [45] have found that the lamellar orientation was not angled 01 or 451 to the growth direction, and other orientations (e.g. 741, 801 and 841) also formed in the DS Ti-47Al-2Cr-2Nb (at%) alloy.…”

“…741, 801 and 841) also formed in the DS Ti-47Al-2Cr-2Nb (at%) alloy. Jung et al [44] and Xiao et al [45,46] have considered that the departure of lamellar orientation resulted from the changed growth direction of b phase.…”

“…The PGD of a phase is shown in Table 4, which was calculated according to the method in Refs. [44][45][46]. The PGD of a phase is /101 1S or /0001S direction at low growth rates (between 1 mm/s and 15 mm/s).…”

Lamellar orientation and growth direction of α phase in directionally solidified Ti-46Al-0.5W-0.5Si alloy

“…These results disagreed with the theoretical predictive results. Jung [16] and Xiao [17,18] have considered that the departure of lamellar orientation resulted from the changed growth directional of b phase. For the a solidification TiAl alloy (Ti-46Al-0.5W-0.5Si at.%), we have found that the lamellar orientation is not always perpendicular to the growth direction under different directional solidification conditions.…”

Effect of growth rate on microstructure and microhardness of directionally solidified Ti-44Al-5Nb-1.5Cr-1.5Zr-1Mo-0.1B alloy

“…Jung et al [23,25] has studied the directionally solidified microstructure of Ti-47Al-2W and found the preferred growth direction of β phase turns <001> to <111> with the growth rates increasing from 30 mm•h -1 to 90 mm•h -1 . Xiao et al [26,27] has found the primary β phase of Ti-47Al-2Cr-2Nb grows along <110> instead of <001> at high temperature gradient during directional solidification.…”