初始组织对Al-Cu-Mg-Zr合金热变形流变应力行为的影响  

Influence of initial microstructures on rheology stress behavior during hot deformation for Al-Cu-Mg-Zr alloy

作　　者：董兆宇 柏国伟 傅定发[1] Dong Zhaoyu;Bo Guowei;Fu Dingfa(College of Materials Science and Engineering, Hunan University, Changsha 410082, China)

机构地区：[1]湖南大学材料科学与工程学院

出　　处：《锻压技术》2019年第7期150-158,共9页Forging & Stamping Technology

基　　金：国家自然科学基金资助项目(51674111)

摘　　要：结合工业生产,对Al-Cu-Mg-Zr合金进行了空冷、水淬和炉冷3种典型的热处理,以得到不同的初始组织。然后对不同初始组织的合金进行等温热压缩实验,实验温度为300~450℃,应变速率为0. 01~10 s-1。结果发现:流变应力随着应变量的增加迅速达到峰值随后软化,最后应力趋于平稳;在3种不同热处理方式中,水淬的峰值应力和动态软化率最大,炉冷的峰值应力和动态软化率最小。通过构建双曲正弦模型,很好地描述了合金流变应力行为。空冷、水淬和炉冷的变形激活能Q值分别为180. 45,298. 92和161. 45 k J·mol-1。Combining industrial production,the heat treatment of Al-Cu-Mg-Zr alloy was carried out by air cooling,water quenching and furnace cooling to obtain different initial microstructures. Then,the isothermal hot compression experiments were performed on alloys with different initial microstructures under the deformation temperature of 300-450 ℃ and the strain rate of 0. 01-10 s-1. The results show that the rheology stress rapidly reaches peak value and then softens into steady with the increasing of strain. In the three different heat treatment methods,the peak stress and dynamic softening rate of water quenching are the largest,and that of furnace cooling are the smallest. The rheology stress behavior of alloy can be described well by the hyperbolic sine equation,and the deformation activation energies of alloy under air cooling,water quenching and furnace cooling are 180. 45,298. 92 and 161. 45 kJ·mol-1,respectively.

关 键 词：Al-Cu-Mg-Zr合金 热压缩 流变应力 本构方程 动态软化率 

分 类 号：TG146.21[一般工业技术—材料科学与工程]