Strain rate effects of dynamic compressive deformation on mechanical properties and microstructure of CoCrFeMnNi high-entropy alloy

Park, Jeong Min; Moon, Jongun; Bae, Jae Wung; Jang, Miso; Park, Jaeyeong; Lee, Sunghak; Kim, Hyoung Seop

doi:10.1016/j.msea.2018.02.031

Cited by 185 publications

(36 citation statements)

References 49 publications

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“…The strain hardening rate at quasi static conditions matches fairly well with that found in the literature [2,6,25]. However, Park et al [6] reported that at the Cantor alloy tested at a strain rate of 4700 s −1 had a higher strain hardening rate than at a strain rate of 10 −4 s −1 . They explained the increase in hardening rate by increased mechanical twinning at 4700 s −1 .…”

Section: Thermomechanical Analysissupporting

confidence: 87%

“…However, only a modest increase in strain hardening rate at low strains (ε = 0.01-0.1) was observed for the samples tested at 750 and 2800 s −1 . The propensity for mechanical twinning depends on grain size, which could explain the differences in the strain hardening behavior at dynamic strain rates observed in the current investigation in comparison with the one reported by Park et al [6].…”

Section: Thermomechanical Analysiscontrasting

confidence: 53%

“…No β values below strain rate of 1 s −1 are reported in this paper as the measurements would require a meticulous analysis of the heat transfer involved. For the calculations of the β, a C p of 430 J/kg K and a ρ of 7.958 g/cm 3 were used [6].…”

Section: Methodsmentioning

confidence: 99%

“…These authors associated the remarkable properties of the CoCrFeMnNi alloy at cryogenic temperatures to the occurrence of deformation-induced twinning and dynamic Hall-Petch effect. Park et al [6] studied the influence of strain rate on the mechanical properties of the CoCrFeMnNi alloy and reported a substantial yield strength dependence on strain rate, as well as different strain hardening behaviors for different strain rates. Furthermore, they also observed the formation of mechanically induced twins and occurrence of adiabatic shear bands on the samples deformed at dynamic strain rates.…”

Section: Introductionmentioning

confidence: 99%

“…In their initial investigations on copper samples, the authors established that the fraction of plastic work converted to heat during plastic deformation was of approximately 0.9. Although it has already been established that β depends on strain, strain rate, and loading mode [12], the assumption of a constant β value of 0.9 for different metallic materials is still common in the recent literature [6,[15][16][17][18][19].…”

Section: Introductionmentioning

confidence: 99%

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Effects of Adiabatic Heating and Strain Rate on the Dynamic Response of a CoCrFeMnNi High-Entropy Alloy

Soares

Patnamsetty

Peura

et al. 2019

J. dynamic behavior mater.

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This work presents a comprehensive analysis of the effects of strain and strain rate on the adiabatic heating and the mechanical behavior of a CoCrFeMnNi high-entropy alloy (HEA). In this investigation, compression tests were carried out at quasi-static and dynamic strain rates. The temperature of the specimens was measured using high speed infrared thermography. The high strain rate tests were conducted with a Split Hopkinson Pressure Bar, and the tests at lower strain rates were performed using a universal testing machine. The material exhibited a positive strain rate sensitivity, as true stress-strain plots were shifted upwards with the increase in strain rate. With exception of the isothermal tests, temperature rise and the Taylor-Quinney coefficient (β) were noticeably similar for the investigated strain rates. This study shows that the common assumption that β can be considered 0.9 and constant is possibly not very accurate for the CoCrFeMnNi alloy. The β is influenced by at least strain and strain rate.

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Section: Thermomechanical Analysissupporting

confidence: 87%

Section: Thermomechanical Analysiscontrasting

confidence: 53%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Effects of Adiabatic Heating and Strain Rate on the Dynamic Response of a CoCrFeMnNi High-Entropy Alloy

Soares

Patnamsetty

Peura

et al. 2019

J. dynamic behavior mater.

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Strain‐Rate Sensitive Deformation Behavior under Tension and Compression of Al_0.3CrFeCoNiMo_0.2

et al. 2021

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Herein, the strain‐rate sensitive deformation behavior of a sintered Al‐ and Mo‐modified CrFeCoNi high‐entropy alloy (HEA) is focused. The sintered microstructure is investigated using scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), energy‐dispersive X‐ray spectroscopy (EDS), and X‐ray diffraction. It was found that after sintering, the microstructure is of very low porosity (<1%) and consists of an ultrafine Mo‐ and Cr‐rich σ phase embedded in a fine‐grained face‐centered cubic (FCC) matrix. Electron microscopy reveals another secondary phase in which Al and Ni are concentrated. For a detailed discussion of the deformation behavior under tension and compression, tensile and compression tests were conducted at strain rates of 10−3, 10, and 102 s−1. Strain‐rate sensitive deformation behavior in terms of strength is observed. The strain hardening rates show no significant strain rate sensitivity (SRS) up to strain rates of 10 s−1. However, at higher strain rates and under compressive loading, a distinctly increased strain hardening rate is found. Tension/compression asymmetry is determined since the SRS value m is twice as high under compression than under tension.

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Toward the Equiaxed Grain Microstructure in CrMnFeCoNi High‐Entropy Alloy Fabricated by Directed‐Energy Deposition

Jin,

Chen,

Dovgyy

et al. 2024

Adv Eng Mater

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The columnar grains in additively manufactured alloys increase tendency to form solidification cracks and cause anisotropy. Studying the effect of process parameters on microstructure development helps to guide the manufacturing of the equiaxed grain microstructure. We firstly studied the effect of process condition on the melt pool dimensions using in‐situ synchrotron X‐ray imaging; and thermal profile and solidification condition using finite element simulation and calculation of thermodynamics phase diagrams of CrMnFeCoNi High‐Entropy Alloy (HEA) fabricated by directed energy deposition (DED). Increasing the laser power reduced the thermal gradient to solidification rate ratio, pushing the solidification closer to the columnar‐equiaxed transition. Nevertheless, the simulations still indicated the columnar microstructure for all scan conditions in contrast to experimental observation that showed single‐wall samples built at 200 W consisted of dominantly equiaxed grains, whereas columnar grains were dominant in samples built at 100 W. It was believed that in addition to the effect of thermal gradient and solidification rate, the chemical segregation (Mn and Ni) during solidification might promote dendrite detachment, hence assisting the transition to equiaxed grains. The multi‐track deposition results in more solid beneath a new melt pool, increasing the thermal gradient that promotes more columnar grains in comparison to single‐tracks.This article is protected by copyright. All rights reserved.

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Strain rate effects of dynamic compressive deformation on mechanical properties and microstructure of CoCrFeMnNi high-entropy alloy

Cited by 185 publications

References 49 publications

Effects of Adiabatic Heating and Strain Rate on the Dynamic Response of a CoCrFeMnNi High-Entropy Alloy

Effects of Adiabatic Heating and Strain Rate on the Dynamic Response of a CoCrFeMnNi High-Entropy Alloy

Strain‐Rate Sensitive Deformation Behavior under Tension and Compression of Al_0.3CrFeCoNiMo_0.2

Toward the Equiaxed Grain Microstructure in CrMnFeCoNi High‐Entropy Alloy Fabricated by Directed‐Energy Deposition

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Strain rate effects of dynamic compressive deformation on mechanical properties and microstructure of CoCrFeMnNi high-entropy alloy

Cited by 185 publications

References 49 publications

Effects of Adiabatic Heating and Strain Rate on the Dynamic Response of a CoCrFeMnNi High-Entropy Alloy

Effects of Adiabatic Heating and Strain Rate on the Dynamic Response of a CoCrFeMnNi High-Entropy Alloy

Strain‐Rate Sensitive Deformation Behavior under Tension and Compression of Al0.3CrFeCoNiMo0.2

Toward the Equiaxed Grain Microstructure in CrMnFeCoNi High‐Entropy Alloy Fabricated by Directed‐Energy Deposition

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Product

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Strain‐Rate Sensitive Deformation Behavior under Tension and Compression of Al_0.3CrFeCoNiMo_0.2