TY - JOUR
T1 - Strain-rate-driven shear mechanisms in additively manufactured CoCrFeMnNi chemically complex alloys
AU - Liu, Shanshan
AU - Hu, Menglei
AU - Meng, Yuquan
AU - Xiao, Lijun
AU - Song, Weidong
N1 - Publisher Copyright:
© 2025 The Authors.
PY - 2025/9/1
Y1 - 2025/9/1
N2 - The single-phase face-centered cubic (FCC) CoCrFeMnNi chemically complex alloy (CCA) was fabricated by selective laser melting (SLM), and the forced shear characteristics were investigated under quasi-static and dynamic loading using hat-shaped specimens with displacement confined by stopper rings. The SLM-printed CCA exhibits excellent shear resistance, with dynamic shear yield and peak strengths reaching ∼320 MPa and ∼661 MPa, respectively, and a maximum shear strain of ∼5.0. A pronounced strain rate sensitivity was observed, as evidenced by the formation of narrow adiabatic shear bands (ASBs, ∼30 μm in width) under high-strain-rate loading, in contrast to much broader shear localization zones (∼150–180 μm) under quasi-static conditions. The localized temperature rise within ASBs promoted rotational dynamic recrystallization (RDRX), resulting in the formation of ultrafine equiaxed grains and a significant reduction in dislocation density and subgrain boundaries. The structural stability and superior shear localization resistance of the SLM-printed CCA under dynamic conditions demonstrate its potential for high-rate impact or ballistic-resistant applications.
AB - The single-phase face-centered cubic (FCC) CoCrFeMnNi chemically complex alloy (CCA) was fabricated by selective laser melting (SLM), and the forced shear characteristics were investigated under quasi-static and dynamic loading using hat-shaped specimens with displacement confined by stopper rings. The SLM-printed CCA exhibits excellent shear resistance, with dynamic shear yield and peak strengths reaching ∼320 MPa and ∼661 MPa, respectively, and a maximum shear strain of ∼5.0. A pronounced strain rate sensitivity was observed, as evidenced by the formation of narrow adiabatic shear bands (ASBs, ∼30 μm in width) under high-strain-rate loading, in contrast to much broader shear localization zones (∼150–180 μm) under quasi-static conditions. The localized temperature rise within ASBs promoted rotational dynamic recrystallization (RDRX), resulting in the formation of ultrafine equiaxed grains and a significant reduction in dislocation density and subgrain boundaries. The structural stability and superior shear localization resistance of the SLM-printed CCA under dynamic conditions demonstrate its potential for high-rate impact or ballistic-resistant applications.
KW - Adiabatic shear band
KW - Chemically complex alloys
KW - Microstructural evolution
KW - Selective laser melting
UR - https://www.scopus.com/pages/publications/105025433029
U2 - 10.1016/j.jmrt.2025.07.270
DO - 10.1016/j.jmrt.2025.07.270
M3 - Article
AN - SCOPUS:105025433029
SN - 2238-7854
VL - 38
SP - 1145
EP - 1153
JO - Journal of Materials Research and Technology
JF - Journal of Materials Research and Technology
ER -