TY - JOUR
T1 - Significance of strain rate in severe plastic deformation on steady-state microstructure and strength
AU - Edalati, Kaveh
AU - Wang, Qing
AU - Enikeev, Nariman A.
AU - Peters, Laura-Jean
AU - Zehetbauer, Michael J.
AU - Schafler, Erhard
N1 - Funding Information:
This work has been supported in part by the Light Metals Educational Foundation of Japan , in part by Grants-in-Aid for Scientific Research on Innovative Areas ( JP19H05176 & JP21H00150 ) and Challenging Research (Exploratory) ( JP22K18737 ) from the MEXT , Japan, and in part by the “Metals and Alloys under Extreme Impacts” Laboratory of Eurasian Center of Excellence, USATU (assignment #075-03-2021-014/4).
Publisher Copyright:
© 2022 Elsevier B.V.
PY - 2022/11/24
Y1 - 2022/11/24
N2 - The microstructure and mechanical properties of materials saturate to steady states after severe plastic deformation (SPD). Despite the well-known effect of temperature on the steady-state microstructure, there is no general agreement on the significance of strain rate and the applicability of the Zener-Hollomon parameter in this regard. In this study, several pure metals (aluminum, copper, titanium, and iron) and a Cu–30Zn (wt%) brass alloy have been processed by a high-speed high-pressure torsion (HPT) equipment with controllable rotation speeds in the range of 0.06–60 rpm. It is found that crystallite/grain size, dislocation density, microhardness and shear stress at the steady state are reasonably rate-independent for the von Mises strain rates in the range of 0.004–20 s−1. Because both rates of grain refinement and of dynamic recrystallization are proportional to the strain rate, it is suggested that their balance, which determines the steady state, is rate-independent.
AB - The microstructure and mechanical properties of materials saturate to steady states after severe plastic deformation (SPD). Despite the well-known effect of temperature on the steady-state microstructure, there is no general agreement on the significance of strain rate and the applicability of the Zener-Hollomon parameter in this regard. In this study, several pure metals (aluminum, copper, titanium, and iron) and a Cu–30Zn (wt%) brass alloy have been processed by a high-speed high-pressure torsion (HPT) equipment with controllable rotation speeds in the range of 0.06–60 rpm. It is found that crystallite/grain size, dislocation density, microhardness and shear stress at the steady state are reasonably rate-independent for the von Mises strain rates in the range of 0.004–20 s−1. Because both rates of grain refinement and of dynamic recrystallization are proportional to the strain rate, it is suggested that their balance, which determines the steady state, is rate-independent.
KW - High-pressure torsion (HPT)
KW - Nanostructured materials
KW - Strain-rate hardening
KW - Ultrafine-grained (UFG) materials
KW - Zener-Hollomon parameter
UR - http://www.scopus.com/inward/record.url?scp=85140922610&partnerID=8YFLogxK
U2 - 10.1016/j.msea.2022.144231
DO - 10.1016/j.msea.2022.144231
M3 - Article
AN - SCOPUS:85140922610
SN - 0921-5093
VL - 859
JO - Materials Science and Engineering A
JF - Materials Science and Engineering A
M1 - 144231
ER -