摘要
研究了TA15钛合金超塑性变形后显微组织的演变及变形条件对超塑性变形行为的影响。结果表明：在变形温度为850～950℃、应变速率为1×10-4～1×10-3s-1超塑性拉伸时，TA15钛合金表现出良好的超塑性变形性能，且在900℃，5．5×10-4s-1变形条件下，延伸率最大为803．3％。在应变速率不变的条件下，随着变形温度的升高，α相晶粒尺寸增大,β相含量增加，晶粒仍保持细小、等轴状态。在变形温度一定时，随着应变速率的降低，α相晶粒尺寸增大，β相含量增加。同时变形程度对显微组织有显著影响，拉伸后不同部位的显微组织均有一定程度的粗化，变形程度越大，晶粒粗化的越明显，并伴有α相到β相的转变。变形过程中，加工硬化与变形软化相互竞争，表现为传统超塑变形的稳态流动特征。
The microstructure evolution and the effect of deformation condition during superplastic deformation behavior of TA15 alloy were investigated. The results showed that, from 850 -950 ℃ deformation temperature and 1 ×10 -4 - 1 ×10 - 3 s - 1 strain rate, TA15 alloy had the good superplastic deformation property. Under deformation condition of 900 ℃ and 5.5 × 10 -4 s-1, it had the biggest e- longation of 803.3 %. In the same strain-rate, the dimension of the α phase grains and the content of phase increased with the tensile temperature increasing, the grains still retained in equiaxed state. At the same deformation temperature, the dimension of the α phase grains and the content of β phase increased with the strain-rate decreasing. Meanwhile, the deformation had a significant influence on the microstructure, different parts of the microstructure had a certain degree of coarsening, greater degree of deformation made coarse- ning more serious, along with α to β phase transform. During deformation, the hardening and the softening competed against each oth- er, and performed the traditional steady-state superplastic flow characteristics.
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2014年第2期328-333,共6页
Chinese Journal of Rare Metals
基金
陕西省科技统筹创新工程计划项目(2011KTCG01-17)资助
关键词
TA15钛合金
超塑性
变形温度
应变速率
显微组织
TA15 titanium alloy
superplasticity
deformation temperature
strain rate
microstructure
