Cryogenic deformation behavior, constitutive modeling and microstructure evolution of solution-treated 2195 Al-Li alloy at high strain rates

TY - JOUR

T1 - Cryogenic deformation behavior, constitutive modeling and microstructure evolution of solution-treated 2195 Al-Li alloy at high strain rates

AU - Chen, Yixi

AU - Yu, Junquan

AU - Ge, Xiqing

AU - Sun, Yutong

AU - Sun, Lu

AU - Zhou, Wenbin

AU - Zhao, Guoqun

N1 - © 2024 Published by Elsevier B.V.

PY - 2024/7/2

Y1 - 2024/7/2

N2 - In this paper, the flow behavior, constitutive model and microstructure evolution of solution-treated 2195 Al-Li alloy at temperatures from 123 K to 298 K and strain rates from 2000 s-1 to 5000 s-1 were studied. Experimental results show that the flow stress of the solution-treated 2195 Al-Li alloy is more sensitive to deformation temperature than strain rate. As the temperature declines from 298 K to 123 K, the flow stress at 2000 s-1 and 5000 s-1 increases by nearly 32.8% and 34.5%, respectively, whereas as the strain rate increases from 2000 s-1 to 5000 s-1, the flow stress at 298 K and 123 K only increases by 5.1% and 6.5%, respectively. The average strain hardening rate tends to decline with the increase in strain rate and temperature, and its value at 123 K and 2000 s-1 is about 2.5 times that at 298 K and 5000 s-1. To overcome the limited applicability of the conventional Arrhenius model with strain compensation, an Arrhenius-based model (c-Arrhenius mode) is developed by coupling an independent strain term and derived using normalized flow stress and linear regression. To quantify the strain rate effect and temperature effect, a Johnson-Cook-based model (c-Johnson-Cook model) with exponential equations is developed. These two new constitutive models are validated via a comparative analysis, showing good predictability and accuracy. A further microstructure observation shows that the dislocation density is the highest at a strain rate of 5000 s-1 and cryogenic temperature of 123 K, which is beneficial for subsequent aging strengthening.

AB - In this paper, the flow behavior, constitutive model and microstructure evolution of solution-treated 2195 Al-Li alloy at temperatures from 123 K to 298 K and strain rates from 2000 s-1 to 5000 s-1 were studied. Experimental results show that the flow stress of the solution-treated 2195 Al-Li alloy is more sensitive to deformation temperature than strain rate. As the temperature declines from 298 K to 123 K, the flow stress at 2000 s-1 and 5000 s-1 increases by nearly 32.8% and 34.5%, respectively, whereas as the strain rate increases from 2000 s-1 to 5000 s-1, the flow stress at 298 K and 123 K only increases by 5.1% and 6.5%, respectively. The average strain hardening rate tends to decline with the increase in strain rate and temperature, and its value at 123 K and 2000 s-1 is about 2.5 times that at 298 K and 5000 s-1. To overcome the limited applicability of the conventional Arrhenius model with strain compensation, an Arrhenius-based model (c-Arrhenius mode) is developed by coupling an independent strain term and derived using normalized flow stress and linear regression. To quantify the strain rate effect and temperature effect, a Johnson-Cook-based model (c-Johnson-Cook model) with exponential equations is developed. These two new constitutive models are validated via a comparative analysis, showing good predictability and accuracy. A further microstructure observation shows that the dislocation density is the highest at a strain rate of 5000 s-1 and cryogenic temperature of 123 K, which is beneficial for subsequent aging strengthening.

KW - Constitutive equation

KW - 2195 Al-Li alloy

KW - Deformation behavior

KW - Deformation band and dislocation

KW - Precipitation strengthening

KW - 2195 Al–Li alloy

KW - Deformation band and dislocation

UR - https://www.scopus.com/pages/publications/85198049269

U2 - 10.1016/j.jmrt.2024.07.013

DO - 10.1016/j.jmrt.2024.07.013

M3 - Article

SN - 2238-7854

VL - 31

SP - 2915

EP - 2929

JO - Journal of Materials Research and Technology

JF - Journal of Materials Research and Technology

ER -