摘要
利用等温热压缩实验建立了7055铝合金的流变应力、位错密度、形核率以及晶粒长大模型,并基于元胞自动机(CA)法模拟研究了7055铝合金在变形温度300~450℃,应变速率0.01~10 s^(-1),真实应变0.7条件下的微观组织演变。结果显示,高温、高应变速率有利于动态再结晶的形核;而高温、低应变速率有利于动态再结晶的充分进行,并能降低微观组织的平均晶粒尺寸,提升材料的组织均匀性。通过CA法模拟获得的流变应力曲线与实验值吻合较好。
The models of flow stress, dislocation density, nucleation rate and grain growth for 7055 aluminum alloy were established by the isothermal compression test. And the microstructure evolution of 7055 aluminum alloy was studied by using cellular automaton method at the deformation temperature from 300 ℃ to 450 ℃, the strain rate from 0.01 s-1 to 10 s-1, and the true strain of 0.7. The results show that high temperature and high strain rate are beneficial to the nucleation of dynamic recrystallization; and high temperature and low strain rate are conducive to the dynamic recrystallization, which can reduce the average grain size of microstructure and enhance the microstructure uniformity of material. The flow stress curves obtained by CA method are in good agreement with the experimental ones.
出处
《热加工工艺》
CSCD
北大核心
2017年第12期235-238,242,共5页
Hot Working Technology
基金
国家重点基础研究发展计划项目(2012CB619505)
国家自然科学基金项目(51405520)
国家科技支撑计划项目(2014BAF12B01)
关键词
元胞自动机
7055铝合金
动态再结晶
流变应力
cellular automaton
7055 aluminum alloy
dynamic recrystallization
flow stress
