含钪Al-Zn-Mg合金的热变形行为和显微组织  

Hot Deformation Behavior and Microstructure of Al-Zn-Mg Alloy Containing Sc During Hot Compression at Elevated Temperature

作　　者：李波[1] 潘清林[1,2] 张志野[1] 李晨[1] 尹志民[1] 

机构地区：[1]中南大学材料科学与工程学院,长沙410083 [2]中南大学有色金属材料科学与工程教育部重点实验室,长沙410083

出　　处：《材料工程》2013年第11期6-11,共6页Journal of Materials Engineering

基　　金：国家重点基础研究计划('973'计划)项目(2012CB619503)

摘　　要：采用Gleeble-1500热模拟试验机对含钪Al-Zn-Mg合金进行热压缩实验,研究了合金在不同热压缩条件下的热变形行为和显微组织。结果表明:合金的流变应力随应变速率的增大而增大,随变形温度的升高而减小。该合金热压缩变形的流变应力行为可用Zener-Hollomon参数来描述,其热变形激活能为150.25kJ/mol。在变形温度为380℃,应变速率为1s-1条件下,合金组织中存在大量的位错墙,表明发生了动态回复现象。随着变形温度的升高,当温度为500℃时,合金中出现了再结晶晶粒,说明主要软化机制逐步由动态回复转变为动态再结晶。The hot compression test of A1-Zn-Mg alloy containing Sc was performed on Gleeble-1500 thermal simulation machine. The hot deformation behavior and microstructural evolution of the alloy were investigated under different deformation conditions. The hot deformation temperature and the strain rate during hot compression tests were 340-500℃, 0. 001-10s-1 , respectively. The results show that the flow stress of the alloy increase with the increasing the strain rate, but decrease with the in- creasing of the deforming temperature. The flow stress of the alloy during hot compression deforma- tion can be described by a Zener-Hollomon parameter. The hot deformation activation energy is 150. 25kJ/mol. When the deformation temperature is 380℃ and the strain rates is ls-1 , the dislocation walls formed and the main soften mechanism is dynamic recovery. When the deformation temperature is 500℃, the recrystallization grains are observed, indicating that the main soften mechanism of the alloy transform from dynamic recovery to dynamic recrystallization.

关 键 词：含钪Al-Zn-Mg合金 热压缩变形 流变应力 显微组织 

分 类 号：TG146.21[一般工业技术—材料科学与工程]