Modelization and comparison of Norton-Hoff and Arrhenius constitutive laws to predict hot tensile behavior of Ti-6Al-4V alloy
(1. School of Large Aircraft, Beihang University, Beijing 100191, China;
2. School of Materials Science and Engineering, Beihang University, Beijing 100191, China;
3. School of Mechanical Engineering and Automation, Beihang University, Beijing 100191, China)
2. School of Materials Science and Engineering, Beihang University, Beijing 100191, China;
3. School of Mechanical Engineering and Automation, Beihang University, Beijing 100191, China)
Abstract: In order to study the workability of Ti-6Al-4V alloy in the hot forming process for sheets and profiles, the stress-strain experimental data from isothermal hot tensile tests of flat specimens, in the temperature range of 923-1023 K and strain rate range of 0.0005-0.05 s-1 were used to develop the constitutive equation. Arrhenius and Norton-Hoff constitutive models were proposed to characterize the tensile behavior. The fitting results suggest that both Arrhenius constitutive equation (material constants consider the compensation of strain) and modified Norton-Hoff one can predict flow stress of Ti-6Al-4V alloy under most experimental conditions. Further, the modified Norton-Hoff model is more accurate and precise than Arrhenius model.
Key words: Ti-6Al-4V alloy; hot tensile behaviour; constitutive model; modelization; Arrhenius model; compensation of strain; modified Norton-Hoff model