Mechanical properties and deformation behavior of dual-phase Al0.6CoCrFeNi high-entropy alloys with heterogeneous structure at room and cryogenic temperatures

Li, Q.; Zhang, T.W.; Qiao, J.W.; Ma, Shuang; Zhao, Dan; Lu, P.; Wang, Z.H.

doi:10.1016/j.jallcom.2019.152663

Cited by 50 publications

(14 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As the Al content increases, there is an evident trend towards stabilizing the BCC phase. As noted before [23][24][25], at low Al fractions (x < 0.3), the equilibrium phase is FCC [43,44], while at larger Al fractions (x ≈ 0.9), the BCC phase becomes stabilized, while mixed FCC-BCC phases are typically found for intermediate Al concentrations [45]. We also explore structures with high Al content, where the FCC phase is recovered, as shown in Figure 2.…”

Section: Resultsmentioning

confidence: 90%

Prediction of Equilibrium Phase, Stability and Stress-Strain Properties in Co-Cr-Fe-Ni-Al High Entropy Alloys Using Artificial Neural Networks

Filipoiu

Nemneş

2020

Metals

View full text Add to dashboard Cite

High entropy alloys (HEAs) are still a largely unexplored class of materials with high potential for applications in various fields. Motivated by the huge number of compounds in a given HEA class, we develop machine learning techniques, in particular artificial neural networks, coupled to ab initio calculations, in order to accurately predict some basic HEA properties: equilibrium phase, cohesive energies, density of states at the Fermi level and the stress-strain relation, under conditions of isotropic deformations. Known for its high tensile ductility and fracture toughness, the Co-Cr-Fe-Ni-Al alloy has been considered as a test candidate material, particularly by adjusting the Al content. However, further enhancement of the microstructure, mechanical and thermal properties is possible by modifying also the fractions of the base alloy. Using deep neural networks, we map structural and chemical neighborhood information onto the quantities of interest. This approach offers the possibility for an efficient screening over a huge number of potential candidates, which is essential in the exploration of multi-dimensional compositional spaces.

show abstract

Section: Resultsmentioning

confidence: 90%

Prediction of Equilibrium Phase, Stability and Stress-Strain Properties in Co-Cr-Fe-Ni-Al High Entropy Alloys Using Artificial Neural Networks

Filipoiu

Nemneş

2020

Metals

View full text Add to dashboard Cite

show abstract

“…Once the microcracks are initiated, the annihilation rate of dislocations is accelerated, resulting in cyclic softening and shortening the fatigue life. Another cyclic-softening source may be related to the SRO or the not high SFE (~49 mJ/m 2 ) 50 in this HEA, causing the slip planarity and leading to the strain localization 24 . In this alloy, Al–Ni and Cr–Fe are the possible SRO pairs in the FCC matrix, as suggested by the large increased Al–Ni and Cr–Fe bonds in the FCC phase (Fig.…”

Section: Discussionmentioning

confidence: 99%

Enhancing fatigue life by ductile-transformable multicomponent B2 precipitates in a high-entropy alloy

et al. 2021

View full text Add to dashboard Cite

Catastrophic accidents caused by fatigue failures often occur in engineering structures. Thus, a fundamental understanding of cyclic-deformation and fatigue-failure mechanisms is critical for the development of fatigue-resistant structural materials. Here we report a high-entropy alloy with enhanced fatigue life by ductile-transformable multicomponent B2 precipitates. Its cyclic-deformation mechanisms are revealed by real-time in-situ neutron diffraction, transmission-electron microscopy, crystal-plasticity modeling, and Monte-Carlo simulations. Multiple cyclic-deformation mechanisms, including dislocation slips, precipitation strengthening, deformation twinning, and reversible martensitic phase transformation, are observed in the studied high-entropy alloy. Its improved fatigue performance at low strain amplitudes, i.e., the high fatigue-crack-initiation resistance, is attributed to the high elasticity, plastic deformability, and martensitic transformation of the B2-strengthening phase. This study shows that fatigue-resistant alloys can be developed by incorporating strengthening ductile-transformable multicomponent intermetallic phases.

show abstract

“…Table 2 provides intuitive data. Although the simultaneous enhancement of strength and ductility of CoCrNi has been reported, it is inspirational that CoCrNiAl 0.1 Si 0.1 has an excellent combination of strength and ductility compared with CoCrNi, CoCrNiFe, CoCrNiFeMn, FeCoCrNiAl x [6,[8][9][10], high-Mn steels [11], austenitic stainless steels [24], and high-Ni steels [25], particularly at 77 K, as shown in Figure 3.…”

Section: Mechanical Propertiesmentioning

confidence: 92%

“…However, CoCrFeMnNi HEA and CoCrNi MEA with medium grain sizes all perform the lower yield strength at ambient temperature, which limits their actual engineering applications [6,7]. It has been pointed out that the additions of alloying elements appropriately that induce lattice distortion is an effective strategy for microstructural design in single-phase alloys, which has been confirmed in some studies of Al, Ti, Mn, and C addition in H-MEAs [8][9][10][11][12][13]. Nevertheless, because of strength and ductility's mutually conflicting relationship, the increase in strength is generally accompanied by a decrease in plasticity, which is called trade-off of strength and plasticity.…”

Section: Introductionmentioning

confidence: 94%

Enhanced Strength and Plasticity of CoCrNiAl0.1Si0.1 Medium Entropy Alloy via Deformation Twinning and Microband at Cryogenic Temperature

Liu¹,

Meng

Chang

et al. 2021

Materials

View full text Add to dashboard Cite

The synthesis of lightweight yet strong-ductile materials has been an imperative challenge in alloy design. In this study, the CoCrNi-based medium-entropy alloys (MEAs) with added Al and Si were manufactured by vacuum arc melting furnace subsequently followed by cool rolling and anneal process. The mechanical responses of CoCrNiAl0.1Si0.1 MEAs under quasi-static (1 × 10−3 s−1) tensile strength showed that MEAs had an outstanding balance of yield strength, ultimate tensile strength, and elongation. The yield strength, ultimate tensile strength, and elongation were increased from 480 MPa, 900 MPa, and 58% at 298 K to 700 MPa, 1250 MPa, and 72% at 77 K, respectively. Temperature dependencies of the yield strength and strain hardening were investigated to understand the excellent mechanical performance, considering the contribution of lattice distortions, deformation twins, and microbands. Severe lattice distortions were determined to play a predominant role in the temperature-dependent yield stress. The Peierls barrier height increased with decreasing temperature, owing to thermal vibrations causing the effective width of a dislocation core to decrease. Through the thermodynamic formula, the stacking fault energies were calculated to be 14.12 mJ/m2 and 8.32 mJ/m2 at 298 K and 77 K, respectively. In conclusion, the enhanced strength and ductility at cryogenic temperature can be attributed to multiple deformation mechanisms including dislocations, extensive deformation twins, and microbands. The synergistic effect of multiple deformation mechanisms lead to the outstanding mechanical properties of the alloy at room and cryogenic temperature.

show abstract

Mechanical properties and deformation behavior of dual-phase Al0.6CoCrFeNi high-entropy alloys with heterogeneous structure at room and cryogenic temperatures

Cited by 50 publications

References 36 publications

Prediction of Equilibrium Phase, Stability and Stress-Strain Properties in Co-Cr-Fe-Ni-Al High Entropy Alloys Using Artificial Neural Networks

Prediction of Equilibrium Phase, Stability and Stress-Strain Properties in Co-Cr-Fe-Ni-Al High Entropy Alloys Using Artificial Neural Networks

Enhancing fatigue life by ductile-transformable multicomponent B2 precipitates in a high-entropy alloy

Enhanced Strength and Plasticity of CoCrNiAl0.1Si0.1 Medium Entropy Alloy via Deformation Twinning and Microband at Cryogenic Temperature

Contact Info

Product

Resources

About