Strengthening and dynamic recrystallization mediated by Si-alloying in a refractory high entropy alloy

2022 ◽  
Vol 832 ◽  
pp. 142480
Author(s):  
Yueling Guo ◽  
Junyang He ◽  
Zhiming Li ◽  
Lina Jia ◽  
Xiaoxiang Wu ◽  
...  
Keyword(s):  
Dynamic Recrystallization ◽  
High Entropy Alloy ◽  
High Entropy

scholarly journals Intermediate-Temperature Creep Deformation and Microstructural Evolution of an Equiatomic FCC-Structured CoCrFeNiMn High-Entropy Alloy

Entropy ◽  
2018 ◽  
Vol 20 (12) ◽  
pp. 960 ◽  
Author(s):  
Chengming Cao ◽  
Jianxin Fu ◽  
Tongwei Tong ◽  
Yuxiao Hao ◽  
Ping Gu ◽  
...  
Keyword(s):  
Activation Energy ◽  
Dynamic Recrystallization ◽  
Creep Deformation ◽  
High Stress ◽  
Intermediate Temperature ◽  
Tensile Creep ◽  
High Entropy Alloy ◽  
High Entropy ◽  
Stress Region ◽  
Stress Dependent

The tensile creep behavior of an equiatomic CoCrFeNiMn high-entropy alloy was systematically investigated over an intermediate temperature range (500–600 °C) and applied stress (140–400 MPa). The alloy exhibited a stress-dependent transition from a low-stress region (LSR-region I) to a high-stress region (HSR-region II). The LSR was characterized by a stress exponent of 5 to 6 and an average activation energy of 268 kJ mol−1, whereas the HSR showed much higher corresponding values of 8.9–14 and 380 kJ mol−1. Microstructural examinations on the deformed samples revealed remarkable dynamic recrystallization at higher stress levels. Dislocation jogging and tangling configurations were frequently observed in LSR and HSR at 550 and 600 °C, respectively. Moreover, dynamic precipitates identified as M23C6 or a Cr-rich σ phase were formed along grain boundaries in HSR. The diffusion-compensated strain rate versus modulus-compensated stress data analysis implied that the creep deformation in both stress regions was dominated by stress-assisted dislocation climb controlled by lattice diffusion. Nevertheless, the abnormally high stress exponents in HSR were ascribed to the coordinative contributions of dynamic recrystallization and dynamic precipitation. Simultaneously, the barriers imposed by these precipitates and severe initial deformation were referred to so as to increase the activation energy for creep deformation.

High temperature deformation behavior and dynamic recrystallization in CoCrFeNiMn high entropy alloy

2015 ◽  
Vol 636 ◽  
pp. 188-195 ◽  
Author(s):  
N.D. Stepanov ◽  
D.G. Shaysultanov ◽  
N.Yu. Yurchenko ◽  
S.V. Zherebtsov ◽  
A.N. Ladygin ◽  
...  
Keyword(s):  
High Temperature ◽  
Dynamic Recrystallization ◽  
Deformation Behavior ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
High Entropy Alloy ◽  
High Entropy

scholarly journals Microstructure Refinement of a Transformation-Induced Plasticity High-Entropy Alloy

Materials ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1196
Author(s):  
Hai-long Yi ◽  
Daixiu Wei ◽  
Ren-yi Xie ◽  
Yi-fan Zhang ◽  
Hidemi Kato
Keyword(s):  
Dynamic Recrystallization ◽  
Strain Rate ◽  
Grain Refinement ◽  
Volume Fraction ◽  
Grain Structure ◽  
Structure Evolution ◽  
High Entropy Alloy ◽  
Transformation Induced Plasticity ◽  
High Entropy ◽  
The Impact

High-entropy alloys (HEAs) have attracted extensive interest due to their unprecedented structure and mechanical performance. We recently proposed a series of novel corich twinning induced plasticity (TWIP) and transformation induced plasticity (TRIP) HEAs with superior tensile properties at room temperature; however, the hot deformation behavior has not been reported. Here, we investigated the dynamic recrystallization behavior and grain refinement of a representative TRIP-HEA, compressed at temperatures of 1123–1273 K with strain rates of 0.1–0.001 s−1. We characterized the impact of the temperature and strain rate on the grain structure evolution. A constitutive equation was constructed to reveal the correlations between the flow stress, strain rate, temperature, and strain. The apparent activation energy was estimated to be ~385.7 kJ/mol. The discontinuous dynamic recrystallization played an important role in the grain refinement, particularly at a relatively higher temperature and a lower strain rate, and the volume fraction and morphology of the recrystallized grains exhibited a strong dependency on the Zener–Hollomon parameter. The study provides guidelines for the grain refinement of HEAs through thermomechanical processing.

scholarly journals Suppressed radiation-induced dynamic recrystallization in CrFeCoNiCu high-entropy alloy

2021 ◽  
Vol 190 ◽  
pp. 158-162
Author(s):  
Jinyeon Kim ◽  
Jong Wook Lim ◽  
Joon Kon Kim ◽  
Do Hyang Kim ◽  
Eun Soo Park ◽  
...  
Keyword(s):  
Dynamic Recrystallization ◽  
High Entropy Alloy ◽  
High Entropy ◽  
Radiation Induced

An investigation into the dynamic recrystallization behavior of a non-equiatomic high entropy alloy

2019 ◽  
Vol 768 ◽  
pp. 138423
Author(s):  
M. Kahnooji ◽  
A. Zarei-Hanzaki ◽  
H.R. Abedi ◽  
M. Hassanpour-Esfahani ◽  
M.S. Jalali ◽  
...  
Keyword(s):  
Dynamic Recrystallization ◽  
High Entropy Alloy ◽  
Recrystallization Behavior ◽  
High Entropy ◽  
Dynamic Recrystallization Behavior

Hot deformation characteristics and dynamic recrystallization of the MoNbHfZrTi refractory high-entropy alloy

2016 ◽  
Vol 651 ◽  
pp. 698-707 ◽  
Author(s):  
N.N. Guo ◽  
L. Wang ◽  
L.S. Luo ◽  
X.Z. Li ◽  
R.R. Chen ◽  
...  
Keyword(s):  
Dynamic Recrystallization ◽  
Hot Deformation ◽  
High Entropy Alloy ◽  
Deformation Characteristics ◽  
High Entropy

Instant and Persistent Hydrogen Production Using Nano High Entropy Catalyst

2019 ◽  
Author(s):  
Nirmal Kumar ◽  
Subramanian Nellaiappan ◽  
Ritesh Kumar ◽  
Kirtiman Deo Malviya ◽  
K. G. Pradeep ◽  
...  
Keyword(s):  
Formic Acid ◽  
Minimum Energy ◽  
High Entropy Alloy ◽  
Hydrogen Energy ◽  
High Entropy ◽  
Electro Oxidation ◽  
The Individual ◽  
Novel Catalyst ◽  
Cell Anode ◽  
Fuel Cell Anode

<div>Renewable harvesting clean and hydrogen energy using the benefits of novel multicatalytic materials of high entropy alloy (HEA equimolar Cu-Ag-Au-Pt-Pd) from formic acid with minimum energy input has been achieved in the present investigation. The synthesis effect of pristine elements in the HEA drives the electro-oxidation reaction towards non-carbonaceous pathway . The atomistic simulation based on DFT rationalize the distinct lowering of the d-band center for the individual atoms in the HEA as compared to the pristine counterparts. This catalytic activity of the HEA has also been extended to methanol electro-oxidation to show the unique capability of the novel catalyst. The nanostructured HEA, properties using a combination of casting and cry omilling techniques can further be utilized as fuel cell anode in direct formic acid/methanol fuel cells (DFFE).<br></div>

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