(1. 中南大学 材料科学与工程学院，长沙 410083；2. 湖南城市学院 土木工程学院，益阳 413000)
摘 要: 采用Gleeble1500热模拟机在应变速率为0.001~10 /s、温度为380~470 ℃、真应变为0~0.7的条件下，研究了实验合金的流变应力行为。结果表明：该合金热压缩变形时存在较明显的稳态流变特征，当
关键字: Al-Zn-Cu-Mg-Sc-Zr合金；热压缩变形；流变应力；Zener-Hollomon参数；热变形激活能
（1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;2. Department of Civil Engineering, Hunan City University, Yiyang 413000, China）
Abstract:The flow stress of the studied alloy over the strain rate of 0.001−10 /s, the temperature of 380−470 ℃ and true strains of 0−0.7 was studied on Gleeble−1500 hot simulator. The experimental results show that the steady-state flow characteristics exist during hot compression deformation in the range of experiments. At lower strain rates( ＜1 /s), the flow stress increases with the increase of strain, then keeps steady and shows dynamic recovery. At high strain rates( ≥1/s), the flow stress decreases after the flow stress reaches obvious peak value with the increase of strain and shows dynamic recrystallization. The flow stress of the alloy during high temperature deformation can be represented by a Zener-Hollomon parameter in the hyperbolic Arrhenius-type equation. Structure factor A, stress level parameter α and stress index n in the analytical expressions of σ are turned to be 5.952×108 /s, 0.021 MPa−1 and 5.397. The average hot deformation activation energy of the alloy is 157.9 kJ/mol.
Key words: Al-Zn-Cu-Mg-Sc-Zr alloy; hot compression deformation; flow stress; Zener-Hollomon parameter; hot deformation activation energy
