摘要
采用Gleeble-1500热模拟试验机对3003铝合金进行变形温度为400℃,应变速率为0.01～10.0 s-1的等温压缩实验,获得热变形过程中的真应力-真应变曲线。结果表明:应变速率ε≥1.0 s-1时,实际变形温度高于预设温度,产生变形热效应。合金发生动态再结晶的临界应变随着应变速率的升高而增加,在较高应变速率条件下(ε≥1.0 s-1),流变应力曲线出现锯齿形波动,合金发生了不连续动态再结晶。利用光学显微镜和透射电镜分析了应变速率对3003铝合金热变形组织演变的影响。结果表明:应变速率越小,合金越容易发生动态再结晶,当应变速率为10.0 s-1时,由于变形热效应的作用,合金也发生了动态再结晶。低应变速率(ε≤0.1 s-1)条件下,提高应变速率可以明显细化晶粒,并且在相同应变下,动态再结晶体积分数随应变速率的增大而减小,综合考虑动态再结晶晶粒的大小和组织均匀性,较佳的应变速率为0.1 s-1。
The isothermal and constant strain rate compression tests of 3003 aluminum alloy were conducted in the strain range of 0.01-10.0 s-1 at 400 ℃ on a Gleeble-1500 thermal simulator.The true stress-true strain curves were obtained in the tests.The results show that the actual deformation temperature of the sample deformed at higher strain rates（≥1.0 s-1） is higher than the preset temperature,resulting in a deformation thermal effect.The critical strain of dynamic recrystallizaion（DRX） increases with strain rate increasing.The serrate flow curves are observed at the higher strain rates（≥1.0 s-1）,which indicates that discontinuous dynamic recrystallization（DDRX） occurs.Optical microscope and transmission electron microscopy were employed to analyze the effect of strain rate on the microstructural evolution.The results show that lower strain rates,more easily DRX occurs.Due to the deformation thermal effect,DRX also takes place in the studied alloys at the strain rate of 10.0 s-1.The grain size can be defined obviously with strain rates increasing at the strain rate higher than 0.1 s-1.Recrystallized volume fraction decreases with strain rate increasing at the same strain.Based on the size of DRX grain and uniformity in the microstructure,the strain rate of 0.1 s-1 is preferable to hot working.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2012年第10期26-31,共6页
Transactions of Materials and Heat Treatment
基金
福建省自然科学基金资助计划项目(E0610004)
福建省教育厅A类科技项目(JA08249)
关键词
3003铝合金
应变速率
动态再结晶
热效应
组织演变
3003 aluminum alloy
strain rate
dynamic recrystallizaion
thermal effect
microstructural evolution
