(1. 中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083；2. 湖南城市學(xué)院 土木工程學(xué)院，益陽 413000)
摘 要: 采用Gleeble1500熱模擬機(jī)在應(yīng)變速率為0.001~10 /s、溫度為380~470 ℃、真應(yīng)變?yōu)?/SPAN>0~0.7的條件下，研究了實(shí)驗(yàn)合金的流變應(yīng)力行為。結(jié)果表明：該合金熱壓縮變形時(shí)存在較明顯的穩(wěn)態(tài)流變特征，當(dāng)
關(guān)鍵字: Al-Zn-Cu-Mg-Sc-Zr合金；熱壓縮變形；流變應(yīng)力；Zener-Hollomon參數(shù)；熱變形激活能
（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
