Abstract
Severe lattice distortion is a core effect in the design of multiprincipal element alloys with the aim to enhance yield strength, a key indicator in structural engineering. Yet, the yield strength values of medium- and high-entropy alloys investigated so far do not substantially exceed those of conventional alloys owing to the insufficient utilization of lattice distortion. Here it is shown that a simple VCoNi equiatomic medium-entropy alloy exhibits a near 1 GPa yield strength and good ductility, outperforming conventional solid-solution alloys. It is demonstrated that a wide fluctuation of the atomic bond distances in such alloys, i.e., severe lattice distortion, improves both yield stress and its sensitivity to grain size. In addition, the dislocation-mediated plasticity effectively enhances the strength–ductility relationship by generating nanosized dislocation substructures due to massive pinning. The results demonstrate that severe lattice distortion is a key property for identifying extra-strong materials for structural engineering applications.
| Original language | English |
|---|---|
| Article number | 1807142 |
| Journal | Advanced Materials |
| Volume | 31 |
| Issue number | 8 |
| DOIs | |
| Publication status | Published - 2019 Feb 22 |
| Externally published | Yes |
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Keywords
- ab initio calculation
- atomic bond distances
- lattice distortion
- medium-entropy alloys
- tensile properties
ASJC Scopus subject areas
- Materials Science(all)
- Mechanics of Materials
- Mechanical Engineering
Cite this
Ultrastrong Medium-Entropy Single-Phase Alloys Designed via Severe Lattice Distortion. / Sohn, Seok S; Kwiatkowski da Silva, Alisson; Ikeda, Yuji; Körmann, Fritz; Lu, Wenjun; Choi, Won Seok; Gault, Baptiste; Ponge, Dirk; Neugebauer, Jörg; Raabe, Dierk.
In: Advanced Materials, Vol. 31, No. 8, 1807142, 22.02.2019.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Ultrastrong Medium-Entropy Single-Phase Alloys Designed via Severe Lattice Distortion
AU - Sohn, Seok S
AU - Kwiatkowski da Silva, Alisson
AU - Ikeda, Yuji
AU - Körmann, Fritz
AU - Lu, Wenjun
AU - Choi, Won Seok
AU - Gault, Baptiste
AU - Ponge, Dirk
AU - Neugebauer, Jörg
AU - Raabe, Dierk
PY - 2019/2/22
Y1 - 2019/2/22
N2 - Severe lattice distortion is a core effect in the design of multiprincipal element alloys with the aim to enhance yield strength, a key indicator in structural engineering. Yet, the yield strength values of medium- and high-entropy alloys investigated so far do not substantially exceed those of conventional alloys owing to the insufficient utilization of lattice distortion. Here it is shown that a simple VCoNi equiatomic medium-entropy alloy exhibits a near 1 GPa yield strength and good ductility, outperforming conventional solid-solution alloys. It is demonstrated that a wide fluctuation of the atomic bond distances in such alloys, i.e., severe lattice distortion, improves both yield stress and its sensitivity to grain size. In addition, the dislocation-mediated plasticity effectively enhances the strength–ductility relationship by generating nanosized dislocation substructures due to massive pinning. The results demonstrate that severe lattice distortion is a key property for identifying extra-strong materials for structural engineering applications.
AB - Severe lattice distortion is a core effect in the design of multiprincipal element alloys with the aim to enhance yield strength, a key indicator in structural engineering. Yet, the yield strength values of medium- and high-entropy alloys investigated so far do not substantially exceed those of conventional alloys owing to the insufficient utilization of lattice distortion. Here it is shown that a simple VCoNi equiatomic medium-entropy alloy exhibits a near 1 GPa yield strength and good ductility, outperforming conventional solid-solution alloys. It is demonstrated that a wide fluctuation of the atomic bond distances in such alloys, i.e., severe lattice distortion, improves both yield stress and its sensitivity to grain size. In addition, the dislocation-mediated plasticity effectively enhances the strength–ductility relationship by generating nanosized dislocation substructures due to massive pinning. The results demonstrate that severe lattice distortion is a key property for identifying extra-strong materials for structural engineering applications.
KW - ab initio calculation
KW - atomic bond distances
KW - lattice distortion
KW - medium-entropy alloys
KW - tensile properties
UR - http://www.scopus.com/inward/record.url?scp=85059250470&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85059250470&partnerID=8YFLogxK
U2 - 10.1002/adma.201807142
DO - 10.1002/adma.201807142
M3 - Article
C2 - 30592339
AN - SCOPUS:85059250470
VL - 31
JO - Advanced Materials
JF - Advanced Materials
SN - 0935-9648
IS - 8
M1 - 1807142
ER -