TY - JOUR
T1 - Evolution of the secondary α phase morphologies during isothermal heat treatment in Ti-7333 alloy
AU - Zhang, Xue
AU - Kou, Hongchao
AU - Li, Jinshan
AU - Zhang, Fengshou
AU - Zhou, Lian
PY - 2013
Y1 - 2013
N2 - Evolution of the secondary α phase morphologies during isothermal heat treatment of a near β titanium alloy Ti-7Mo-3Al-3Nb-3Cr (Ti-7333) has been studied by using SEM and TEM. The results indicated that the morphologies of α phase widely varied by changing the isothermal temperature and time. The needle- like secondary α precipitate morphology formed after solution treatment above β transus followed with aging treatment. When the aging temperature reduced, the length and width of α phase reduced while the volume fraction increased. This increasing in the volume fraction of α phase resulted in the strengthening of the micro-hardness of the alloy. In addition, the results showed that there was almost no precipitation after 1 min isothermal holding time at 650 °C. After 2 min, α phase presented a dot shape precipitation with a nonuniform distribution. Increasing the holding time to 5 min, the α precipitation demonstrated a needle-like shape. At last, the coarse α precipitation formed after aging 3 h. The volume fraction of α increased from 4.6% to 44% while the aging time increasing from 2 min to 3 h. The effect of the alloy elements on governing the microstructure is discussed.
AB - Evolution of the secondary α phase morphologies during isothermal heat treatment of a near β titanium alloy Ti-7Mo-3Al-3Nb-3Cr (Ti-7333) has been studied by using SEM and TEM. The results indicated that the morphologies of α phase widely varied by changing the isothermal temperature and time. The needle- like secondary α precipitate morphology formed after solution treatment above β transus followed with aging treatment. When the aging temperature reduced, the length and width of α phase reduced while the volume fraction increased. This increasing in the volume fraction of α phase resulted in the strengthening of the micro-hardness of the alloy. In addition, the results showed that there was almost no precipitation after 1 min isothermal holding time at 650 °C. After 2 min, α phase presented a dot shape precipitation with a nonuniform distribution. Increasing the holding time to 5 min, the α precipitation demonstrated a needle-like shape. At last, the coarse α precipitation formed after aging 3 h. The volume fraction of α increased from 4.6% to 44% while the aging time increasing from 2 min to 3 h. The effect of the alloy elements on governing the microstructure is discussed.
KW - Isothermal heat treatment
KW - Near β titanium alloy
KW - α Phase
KW - α Variant
UR - http://www.scopus.com/inward/record.url?scp=84884470415&partnerID=8YFLogxK
U2 - 10.1016/j.jallcom.2013.06.180
DO - 10.1016/j.jallcom.2013.06.180
M3 - 文章
AN - SCOPUS:84884470415
SN - 0925-8388
VL - 577
SP - 516
EP - 522
JO - Journal of Alloys and Compounds
JF - Journal of Alloys and Compounds
ER -