scholarly journals Polymorphic Transformation and Magnetic Properties of Rapidly Solidified Fe26.7Co26.7Ni26.7Si8.9B11.0 High-Entropy Alloys

Materials ◽  
2019 ◽  
Vol 12 (4) ◽  
pp. 590 ◽  
Author(s):  
Zequn Zhang ◽  
Kaikai Song ◽  
Ran Li ◽  
Qisen Xue ◽  
Shuang Wu ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Amorphous Alloys ◽  
Polymorphic Transformation ◽  
Supersaturated Solid Solution ◽  
High Entropy Alloys ◽  
High Entropy ◽  
Magnetic Performance ◽  
Increasing Temperature ◽  
Rapidly Solidified ◽  
Bcc Phase

In this work, the microstructural evolution and magnetic performance of the melt-spun amorphous and amorphous-crystalline Fe26.7Co26.7Ni26.7Si8.9B11.0 high-entropy alloys (HEAs) during crystallization were investigated, respectively. Upon heating fully amorphous ribbons, a metastable BCC supersaturated solid solution together with a little Ni31Si12 crystals first precipitated and then the (Fe,Co)2B crystals formed until the full crystallization was achieved. With further increasing temperature after full crystallization, a polymorphic transformation from a metastable BCC phase to two types of FCC solid solutions occurred. For the amorphous-crystalline HEAs, the dominant crystallization products were the metastable FCC but not BCC crystals. During crystallization, the primary metastable FCC crystals first transform into the metastable BCC crystals and then the newly-generated BCC phase transforms into two types of FCC phases with further increasing temperature. This temperature dependence of the gradual polymorphic transformation results in the change of magnetic properties of the present high-entropy amorphous alloys.

scholarly journals Effects of La on Thermal Stability, Phase Formation and Magnetic Properties of Fe–Co–Ni–Si–B–La High Entropy Alloys

Metals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1907
Author(s):  
Jiaming Li ◽  
Jianliang Zuo ◽  
Hongya Yu
Keyword(s):  
Thermal Stability ◽  
Magnetic Properties ◽  
Saturation Magnetization ◽  
Phase Formation ◽  
Crystallization Temperature ◽  
High Entropy Alloys ◽  
Soft Magnetic Properties ◽  
Soft Magnetic ◽  
High Entropy ◽  
Bcc Phase

The microstructure, phase formation, thermal stability and soft magnetic properties of melt-spun high entropy alloys (HEAs) Fe27Co27Ni27Si10−xB9Lax with various La substitutions for Si (x = 0, 0.2, 0.4, 0.6, 0.8, and 1) were investigated in this work. The Fe27Co27Ni27Si10−xB9La0.6 alloy shows superior soft magnetic properties with low coercivity Hc of ~7.1 A/m and high saturation magnetization Bs of 1.07 T. The content of La has an important effect on the primary crystallization temperature (Tx1) and the secondary crystallization temperature (Tx2) of the alloys. After annealing at relatively low temperature, the saturation magnetization of the alloy increases and the microstructure with a small amount of body-centered cubic (BCC) phase embedded in amorphous matrix is observed. Increasing the annealing temperature reduces the magnetization due to the transformation of BCC phase into face-centered cubic (FCC) phase.

scholarly journals Magnetic Properties and Microstructure of FeCoNi(CuAl)0.8Snx (0 ≤ x ≤ 0.10) High-Entropy Alloys

Entropy ◽  
2018 ◽  
Vol 20 (11) ◽  
pp. 872 ◽  
Author(s):  
Zhong Li ◽  
Chenxu Wang ◽  
Linye Yu ◽  
Yong Gu ◽  
Minxiang Pan ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
High Entropy Alloys ◽  
Face Centered Cubic ◽  
High Tc ◽  
Soft Magnets ◽  
High Entropy ◽  
Face Centered ◽  
Fcc Phase ◽  
Bcc Phase ◽  
Curie Temperatures

The present work exhibits the effects of Sn addition on the magnetic properties and microstructure of FeCoNi(CuAl)0.8Snx (0 ≤ x ≤ 0.10) high-entropy alloys (HEAs). The results show all the samples consist of a mixed structure of face-centered-cubic (FCC) phase and body-centered-cubic (BCC) phase. The addition of Sn promotes the formation of BCC phase, and it also affects the shape of Cu-rich nano-precipitates in BCC matrix. It also shows that the Curie temperatures (Tc) of the FCC phase and the saturation magnetization (Ms) of the FeCoNi(CuAl)0.8Snx (0 ≤ x ≤ 0.10) HEAs increase greatly while the remanence (Br) decreases after the addition of Sn into FeCoNi(CuAl)0.8 HEA. The thermomagnetic curves indicate that the phases of the FeCoNi(CuAl)0.8Snx (0 ≤ x ≤ 0.10) HEAs will transform from FCC with low Tc to BCC phase with high Tc at temperature of 600–700 K. This work provides a new idea for FeCoNi(CuAl)0.8Snx (0 ≤ x ≤ 0.10) HEAs for their potential application as soft magnets to be used at high temperatures.

scholarly journals Brute Force Composition Scanning with a CALPHAD Database to Find Low Temperature Body Centered Cubic High Entropy Alloys

Entropy ◽  
2018 ◽  
Vol 20 (12) ◽  
pp. 911 ◽  
Author(s):  
T. Klaver ◽  
D. Simonovic ◽  
M. Sluiter
Keyword(s):  
Low Temperature ◽  
Grid Point ◽  
Ternary Alloys ◽  
High Entropy Alloy ◽  
High Entropy Alloys ◽  
Body Centered Cubic ◽  
High Entropy ◽  
Increasing Temperature ◽  
Bcc Phase

We used the Thermo-Calc High Entropy Alloy CALPHAD database to determine the stable phases of AlCrMnNbTiV, AlCrMoNbTiV, AlCrFeTiV and AlCrMnMoTi alloys from 800 to 2800 K. The concentrations of elements were varied from 1–49 atom%. A five- or six-dimensional grid is constructed, with stable phases calculated at each grid point. Thermo-Calc was used as a massive parallel tool and three million compositions were calculated, resulting in tens of thousands of compositions for which the alloys formed a single disordered body centered cubic (bcc) phase at 800 K. By filtering out alloy compositions for which a disordered single phase persists down to 800 K, composition ‘islands’ of high entropy alloys are determined in composition space. The sizes and shapes of such islands provide information about which element combinations have good high entropy alloy forming qualities as well as about the role of individual elements within an alloy. In most cases disordered single phases are formed most readily at low temperature when several elements are almost entirely excluded, resulting in essentially ternary alloys. We determined which compositions lie near the centers of the high entropy alloy islands and therefore remain high entropy islands under small composition changes. These island center compositions are predicted to be high entropy alloys with the greatest certainty and make good candidates for experimental verification. The search for high entropy islands can be conducted subject to constraints, e.g., requiring a minimum amount of Al and/or Cr to promote oxidation resistance. Imposing such constraints rapidly diminishes the number of high entropy alloy compositions, in some cases to zero. We find that AlCrMnNbTiV and AlCrMoNbTiV are relatively good high entropy alloy formers, AlCrFeTiV is a poor high entropy alloy former, while AlCrMnMoTi is a poor high entropy alloy former at 800 K but quickly becomes a better high entropy alloy former with increasing temperature.

Effect of grain and phase boundaries on soft magnetic properties of FeCoNiAlSi high-entropy alloys

2021 ◽  
pp. 129965
Author(s):  
Zhong Li ◽  
Jianing Qi ◽  
Zhuangzhuang Li ◽  
Hongxia Li ◽  
Hui Xu ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
High Entropy Alloys ◽  
Soft Magnetic Properties ◽  
Soft Magnetic ◽  
Phase Boundaries ◽  
High Entropy

Effects of phase composition and elemental partitioning on soft magnetic properties of AlFeCoCrMn high entropy alloys

2019 ◽  
Vol 171 ◽  
pp. 31-39 ◽  
Author(s):  
Chanwon Jung ◽  
Ku Kang ◽  
Amalraj Marshal ◽  
Konda Gokuldoss Pradeep ◽  
Jae-Bok Seol ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Phase Composition ◽  
High Entropy Alloys ◽  
Soft Magnetic Properties ◽  
Soft Magnetic ◽  
High Entropy

scholarly journals The AC Soft Magnetic Properties of FeCoNixCuAl (1.0 ≤ x ≤ 1.75) High-Entropy Alloys

Materials ◽  
2019 ◽  
Vol 12 (24) ◽  
pp. 4222 ◽  
Author(s):  
Zhongyuan Wu ◽  
Chenxu Wang ◽  
Yin Zhang ◽  
Xiaomeng Feng ◽  
Yong Gu ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Soft Magnetic Materials ◽  
Magnetic Flux Density ◽  
High Entropy Alloys ◽  
Soft Magnetic Properties ◽  
Phase Content ◽  
Soft Magnetic ◽  
High Entropy ◽  
Two Phases ◽  
Fcc Phase

High-entropy alloys (HEAs) with soft magnetic properties are one of the new candidate soft magnetic materials which are usually used under an alternating current (AC) magnetic field. In this work, the AC soft magnetic properties are investigated for FeCoNixCuAl (1.0 ≤ x ≤ 1.75) HEAs. The X-ray diffraction (XRD) and scanning electron microscope (SEM) show that the alloy consists of two phases, namely a face-centred cubic (FCC) phase and a body-centred cubic (BCC) phase. With increasing Ni content, the FCC phase content increased. Further research shows that the AC soft magnetic properties of these alloys are closely related to their phase constitution. Increasing the FCC phase content contributes to a decrease in the values of AC remanence (AC Br), AC coercivity (AC Hc) and AC total loss (Ps), while it is harmful to the AC maximum magnetic flux density (AC Bm). Ps can be divided into two parts: AC hysteresis loss (Ph) and eddy current loss (Pe). With increasing frequency f, the ratio of Ph/Ps decreases for all samples. When f ≤ 150 Hz, Ph/Ps > 70%, which means that Ph mainly contributes to Ps. When f ≥ 800 Hz, Ph/Ps < 40% (except for the x = 1.0 sample), which means that Pe mainly contributes to Ps. At the same frequency, the ratio of Ph/Ps decreases gradually with increasing FCC phase content. The values of Pe and Ph are mainly related to the electrical resistivity (ρ) and the AC Hc, respectively. This provides a direction to reduce Ps.

Phase transitions and magnetic properties of Fe30Co29Ni29Zr7B4Cu1 high-entropy alloys

2019 ◽  
Vol 789 ◽  
pp. 762-767 ◽  
Author(s):  
Ran Wei ◽  
Hang Zhang ◽  
Hongyan Wang ◽  
Chen Chen ◽  
Tan Wang ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Phase Transitions ◽  
High Entropy Alloys ◽  
High Entropy

scholarly journals Thermal Expansion, Elastic and Magnetic Properties of FeCoNiCu-Based High-Entropy Alloys Using First-Principle Theory

JOM ◽  
2017 ◽  
Vol 69 (11) ◽  
pp. 2107-2112 ◽  
Author(s):  
Shuo Huang ◽  
Ádám Vida ◽  
Anita Heczel ◽  
Erik Holmström ◽  
Levente Vitos
Keyword(s):  
Magnetic Properties ◽  
Thermal Expansion ◽  
High Entropy Alloys ◽  
First Principle ◽  
High Entropy ◽  
Principle Theory

scholarly journals The effect of cooling rate on the magnetic properties of Cu-Fe-Ni multicomponent alloys with Al and Si additions

2018 ◽  
Vol 26 (1) ◽  
pp. 39-44
Author(s):  
O. I. Kushnerov ◽  
V. F. Bashev
Keyword(s):  
Magnetic Properties ◽  
Cooling Rate ◽  
Alloy System ◽  
Enthalpy Of Mixing ◽  
Soft Magnetic Materials ◽  
High Entropy Alloys ◽  
High Entropy ◽  
Leading Role ◽  
The Difference ◽  
Fcc Phase

The paper explores the structure and magnetic properties of multicomponent high-entropy Al-Cu-Fe-Ni-Si alloys in as-cast and splat-quenched state. This alloy system is characterized by the absence of expensive components, such as Co, V, Mo, Cr, usually used for the production of high-entropy alloys while its characteristics are not inferior to those of more expensive alloys. Components of the studied high-entropy alloys were selected taking into account both criteria for designing and estimating their phase composition, which are available in the literature and based on the calculations of the entropy and enthalpy of mixing, and the difference between atomic radii of components as well. The alloy films were fabricated by a known technique of splat-quenching. A cooling rate estimated by film thickness was ~ 106 K/s. Experimental results reveal that the studied alloys except the Al0.5CuFeNi one are multiphase, with the structure consisting of disordered BCC and FCC solid solutions. The Al0.5CuFeNi alloy has only FCC phase. The leading role in determining the type of solid solution formed in the studied high-entropy films obviously plays an element with the highest melting point. All of the investigated multicomponent films are soft magnetic materials as indicated by low values of coercivity, while most of the as-cast alloys are hard-magnetic.

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