摘要
采用d-电子合金设计法设计了一种β钛合金,Ti-6Mo-5V-3Al-2Fe(质量分数)。在450~600℃范围内选取了多个时效温度进行时效处理,以研究时效温度对该合金组织演变及力学性能的影响。结果表明,当时效温度为500℃时,在ω辅助形核机制作用下,形成了尺寸和相间距更小的次生α相,在此细小的次生α相对β基体的强化作用下合金抗拉强度达到最大值1510 MPa;同时,由于晶界α相的析出以及晶界无析出区的形成,导致合金的塑性极差,伸长率仅为4.6%。随着时效温度的升高,晶内细小的次生α相粗化。粗大的次生α相导致其相间距增大,并使可有效阻碍位错运动的α/β相界面减小。时效温度的升高使合金强度降低,但合金塑性提高。当时效温度升高至600℃,在β晶界处形成了向晶内平行生长的板条状次生α相,同时β晶粒内次生α相间距增大,使合金塑性明显提高,伸长率可达12.2%。
A β titanium alloy Ti-6 Mo-5 V-3 Al-2 Fe(wt%) was designed in terms of d-electron alloy design method. Aging treatment was performed at various temperatures ranging from 450 °C to 600 °C for 4 h to study the effect of aging temperature on microstructure evolution and tensile properties. The results show that the secondary α phase with smaller size and inter-particle spacing forms under ω-assisted nucleation mechanism at the aging temperature of 500 °C. The highest ultimate tensile strength of 1510 MPa is obtained due to the strengthening of fine acicular secondary α phases within β grains, while poor elongation of 4.6% is found as a result of the inevitable precipitation of α phase at grain boundaries and the formation of precipitate free zone near grain boundaries. Fine secondary α precipitates tend to coarsen with increasing the aging temperature. Coarse α precipitates can bring about broad inter-particle spacing and result in less α/β interfaces that act as effective dislocation barriers. The increase of aging temperature leads to the variation of tensile properties, i.e. the strength decreases while ductility changes in an opposite way. A considerable improvement of elongation to 12.2% is achieved by increasing the aging temperature to 600 °C, in association with the formation of parallel α colony near β grain boundaries and broad inter-particle spacing of secondary α phases within β grains.
作者
张浩宇
黎小辉
林立
张思倩
王川
陈立佳
Zhang Haoyu;Li Xiaohui;Lin Li;Zhang Siqian;Wang Chuan;Chen Lijia(Guangdong Provincial Key Laboratory for Technology and Application of Metal Toughening,Guangzhou 510650,China;Shenyang University of Technology,Shenyang 110870,China;Shenyang Aerospace Xinguang Group Co.,Ltd,Shenyang 110861,China)
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2019年第12期3812-3818,共7页
Rare Metal Materials and Engineering
基金
Foundation of Guangdong Provincial Key Laboratory for Technology and Application of Metal Toughening（GKL201608）
Foundation of Liaoning Province Educational Committee（LGD2016019）
关键词
Β钛合金
时效处理
次生α相
显微组织
力学性能
β titanium alloy
aging
secondary α phase
microstructure
mechanical properties
