摘要
针对名义成分为Ti-46Al-3.8(V,Cr,Ni)(at%)的挤压TiAl合金,研究了热处理工艺对高温时β相含量、形貌的影响,利用高温时β相对α相晶粒的钉扎作用获得了层片团尺寸均匀、细小的全层片组织,测试了具有该组织合金的拉伸性能。结果表明,在1320～1370℃范围内,随保温温度的升高,β相含量逐渐增加,使得合金的晶粒尺寸逐渐减小。实验合金经1340℃/5min/AC热处理后可以获得层片团(尺寸平均为65μm),B2相弥散分布的全层片组织。该组织的室温及高温拉伸性能均较好。少量B2相对合金的室温塑性无不利影响,对合金的高温强度可能有一定贡献。
For the extruded alloy with the nominal composition of Ti-46Al-3.8（V, Cr, Ni） （at%）, the effect of heat treatment on the morphology and volume fraction offl phase was investigated. Refined fully lamellar microstructure with uniform colony size was obtained by the pinning effect of fl phase on the a phase at high temperature. The tensile properties of refined fully lamellar microstructure were tested. The results show that the colony size decreases gradually due to more fl phases within 1320-1370℃ as the temperature increases. The colony size of the alloy after 1340℃/5 min/AC heat treatment is 65 p.m and the B2 phase distributes dispersedly. This microstructure possesses superior tensile properties at room temperature and high temperature. A few of B2 phases do not affect the ductility of the alloy at room temperature （RT）, and may help to increase tensile stress at high temperature.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2012年第10期1846-1850,共5页
Rare Metal Materials and Engineering
基金
中国科技部高新技术项目(G07050350)
关键词
挤压TiAl合金
热处理
B2相
细小全层片组织
extruded TiAl alloy
heat treatment
B2 phase
refined fully lamellar microstructure
