7B50铝合金热变形组织演变  

Microstructure Evolution of 7B50 Alloy During Hot Deformation

作　　者：周坚[1] 潘清林[1,2] 张志野[1] 陈琴[1] 

机构地区：[1]中南大学材料科学与工程学院,湖南长沙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,湖南长沙410083

出　　处：《热加工工艺》2012年第2期20-23,132,共5页Hot Working Technology

基　　金：国家高技术研究发展计划资助项目(2006AA03Z523)

摘　　要：利用Gleeble-1500热模拟试验机对7B50铝合金进行了变形温度300～460℃、应变速率0.001～1 s-1条件下的等温压缩试验,通过金相显微镜(OM)和透射电镜(TEM)等手段,研究分析了该合金在变形过程中热变形参数对微观组织的影响。结果表明:在变形初期,流变应力随应变的增加而增大,达到峰值后逐渐趋于平稳;应力峰值随温度的升高而减小,随应变速率的提高而增大;当变形温度较低或应变速率较高时,合金仅发生了动态回复,且合金组织中存在大量的位错和亚晶;随着温度的升高和应变速率的降低,合金中的主要软化机制由动态回复逐渐转变为动态再结晶。The isothermal axisymmetric hot compression tests of 7B50 alloy were performed on a Gleeble-1500 thermal mechanical simulator at the temperatures ranging from 300 ℃ to 460 ℃ and the strain rates ranging from 0.001 to 1 s-1.Optical microscope（OM） and transmission electron microscope（TEM） were employed to analyze the micro-structural evolution of the alloy under different deformation conditions.The results show that the flow stress increases with increasing strain and tends to be constant after a peak value;the peak stress decreases with increasing the temperature,and increases with increasing the strain rate.At low deformation temperatures and high strain rates,only dynamic recovery occurs in the alloy,and a large number of dislocations and metastable crystallines are observed in the alloy.With increasing the deformation temperature and decreasing the strain rate,the main soften mechanism of 7B50 alloy transforms from dynamic recovery into dynamic recrystallization.

关 键 词：7B50铝合金 热压缩变形 微观组织 动态再结晶 

分 类 号：TG131[一般工业技术—材料科学与工程]