摘要
利用金相(OM)、透射电镜(TEM)对7075铝合金热变形显微组织进行了观察。实验表明:在热锻条件下,7075铝合金完全可以发生动态再结晶并通过动态再结晶产生细小的再结晶晶粒。动态再结晶的方式为不连续动态再结晶,形核机制为亚晶转动、聚合形核;其临界应变值和加工道次有关,道次越多,临界值越低。在相同Z值下,再结晶晶粒尺寸随着应变的增加而减小。弥散的第二相粒子在动态再结晶过程中起了重要作用。
The 7075 aluminum alloy is forged at different strain in different ways. OM(optical microscope) and TEM(transmission electric microscope) were employed to observe the microstructure of 7075 aluminum alloy after hot deformation. Experiment results indicated that 7075 aluminum can occur dynamic recrystallization under hot forging and fine grain can be obtained at the same time, whose recrystallization mechanism and nucleation mechanism are discontinuous dynamic recrystallization and subgrain rotation and polymerization respectively. Its critical strain value is related to deformation pass, the more passes are, the smaller critical strain value will become. Recrystallized grain size decreases with increase of strain, and dispersed second-phase particles play a very important role during dynamic recrystallization.
出处
《稀有金属材料与工程》
SCIE
EI
CAS
CSCD
北大核心
2004年第8期827-830,共4页
Rare Metal Materials and Engineering
基金
国家重点基础项目(G1999064908-04)
关键词
7075铝合金
动态再结晶
临界应变
第二相粒子
7075 aluminum alloy
critical strain
dynamic recrystallization
second-phase particles
