含钪2099铝-锂合金热压缩变形行为及其组织演变  

Hot compression deformation behavior and microstructure evolution of 2099 Al-Li alloy with Sc addition

作　　者：徐安林[1] 李博 

机构地区：[1]无锡职业技术学院智能制造工程中心,江苏无锡214121 [2]中南大学材料科学与工程学院,湖南长沙410083

出　　处：《轻合金加工技术》2018年第3期50-55,共6页Light Alloy Fabrication Technology

基　　金：江苏高校品牌专业建设工程一期项目-数控技术专业(PPZY2015A086)

摘　　要：利用Gleeble-3800热模拟试验机进行热变形实验,开展含钪2099铝-锂合金的热变形行为研究。研究表明:在热变形初期,随着应变量的增加,流变应力呈急剧上升的趋势。在应变量为0.06左右时,合金在各变形条件下的流变应力均达到峰值;当应变量继续增加时,合金的流变应力开始出现不同程度的下降。ln[sinh(ασ)]与lnε·以及ln[sinh(ασ)]与1/T之间满足线性关系,其平均热变形激活能为182.451 k J/mol,合金热压缩变形时的流变应力方程为ε·=2.05×10^(16)[sinh(0.01752σ)]^(6.542)exp(-182451/RT)。在变形温度为400℃,应变速率为1 s^(-1)条件下,合金组织中存在大量的位错墙;随着应变速率的降低,当应变速率为0.01 s^(-1)时,合金内部可以观察到少量动态再结晶组织。Hot compression deformation behavior of 2099 Al-Li alloy with Sc addition was studied by hot compression tests performed on a Gleeble-3800 thermal mechanical simulator. The experimental results show that at the beginning of the hot deformation, the flow stress in- creases sharply with the increase of the strain. When the strain is about 0.06, the flow stress reaches the peak whatever the deformation is; the flow stress begins to decrease gradually in different extent with the increase of the strain. The relationship between in [ sinh （ασ） ] and lnA and between In[ Sin/t（ασ） ] and 1/T satisfies the linear type and the average hot deform- ation activation energy is 182. 451 kJ/mol. The flow stress equation is σ = 2. 05 ×10^6 [sinh（0. 01752σ）]6542exp（- 182451/RT） . When the deformation temperature is 400℃ and the strain rate is 1 s ^- 1, a large number of dislocation walls are formed ; With the decrease of strain rates（0. 01 s^-1） , a few dynamic recrystallization grains can be observed.

关 键 词：含钪2099铝-锂合金 热激活能 本构方程 显微组织 

分 类 号：TG319[金属学及工艺—金属压力加工]