摘要
在Gleeble-1500热模拟机上对Al-Mn-Mg-RE合金进行等温热压缩试验,变形温度300～500℃,应变速率0.01～10s-1。结果表明:Al-Mn-Mg-RE合金流变应力均随应变的增加而迅速增大至峰值,之后随应变的增加而呈不同程度的减小。峰值应力随着变形温度的升高和应变速率的降低而逐渐减小;采用Zener-Hollomon模型和温度补偿的应变速率因子Z参数值的双曲正弦模型来描述该合金热压缩变形流变应力行为,其热变形激活能为186.482kJ/mol;在高Z值条件下的变形组织是拉长晶的亚晶内存在大量位错,而在低Z值条件下再结晶组织内形成了完整的亚晶结构。
The hot compression tests of Al-Mn-Mg-RE alloy were performed at 300 ℃～500 ℃ under the strain rate of 0.01 s-1～10 s-1 on Gleeble-1500 system.The results show that the true stress-true strain curves exhibit a peak stress at a critical strain,and then,the flow stress decreases monotonically.The peak stress decreases as the deformation temperature increasing and strain rate decreasing,which can be represented by Zener-Hollomon parameter Z in the hyperbolic-sine equation with the hot deformation activation energy of 186.482 kJ/mol.The deformed microstructure consists of a great amount of dislocations within subgrains in the elongated grains at high Z value,but exhibits well formed subgrains in the recrystallized grains at low Z value.
出处
《热加工工艺》
CSCD
北大核心
2012年第2期91-94,共4页
Hot Working Technology
