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

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

Materials ◽

10.3390/ma12244222 ◽

2019 ◽

Vol 12 (24) ◽

pp. 4222 ◽

Cited By ~ 2

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.

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The effect of cooling rate on structure and mechanical properties of Co-Cr-Cu-Fe-Ni-Sn high entropy alloys

Journal of Physics and Electronics ◽

10.15421/332114 ◽

2021 ◽

Vol 29 (1) ◽

pp. 85-90

Author(s):

O. I. Kushnerov ◽

V. F. Bashev

Keyword(s):

Mechanical Properties ◽

Cooling Rate ◽

Enthalpy Of Mixing ◽

High Entropy Alloys ◽

Alloy Structure ◽

Simultaneous Formation ◽

High Entropy ◽

Splat Quenching ◽

The Difference ◽

Atomic Radii

The paper examines the structure and mechanical properties of multicomponent high-entropy CoCrCuFeNiSnx alloys in as-cast and splat-quenched states. The compositions of investigated alloys is analyzed by using the criteria for predicting the phase composition of high-entropy alloys available in the literature, based both on calculations of the entropy and enthalpy of mixing and on an estimate of the difference between the atomic radii of the component. The alloy films is fabricated by the known technique of splat-quenching. A cooling rate estimated by a film thickness is ~ 106 K/s. The simultaneous formation of two solid solutions (FCC + ordered BCC) has been established in the alloy structure. An increase in the concentration of Sn favors the formation of the ordered (В2 type) solid solution in the structure of the alloys. High values of the microhardness and dislocation density have been obtained in the splat-quenched samples. It is also shown that an increase in the Sn content positively affects the microhardness.

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

Entropy ◽

10.3390/e20110872 ◽

2018 ◽

Vol 20 (11) ◽

pp. 872 ◽

Cited By ~ 8

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.

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Microstructures and compressive properties of AlxCoCrFeNi high entropy alloys prepared by arc melting and directional solidification

Materials Research Express ◽

10.1088/2053-1591/ac4882 ◽

2022 ◽

Author(s):

Zhuhuan Yu ◽

Yawen Yan ◽

Wei Gao ◽

Xiaohui Wang ◽

Xuliang Liu ◽

...

Keyword(s):

Directional Solidification ◽

Energy Dispersive Spectrometer ◽

Solidification Process ◽

High Entropy Alloys ◽

Directionally Solidified ◽

High Entropy ◽

Phase Constituent ◽

Arc Melting ◽

The Difference ◽

Fcc Phase

Abstract The AlxCoCrFeNi (molar radio, x=0.6 and 1.2) high entropy alloys (HEAs) were prepared by arc melting and directional solidification at the withdrawal rate of 150 μm/s. All microstructures were characterized by x-ray diffraction, optical microscopy and scanning electron microscopy with an energy-dispersive spectrometer. Strong similarities in phase constituent were observed between the as-cast samples and directionally solidified samples. The Al0.6CoCrFeNi HEA and Al1.2CoCrFeNi HEA fabricated by two different techniques respectively consisted of Cr-Fe-Co enriched FCC phase + Al-Ni enriched BCC phase and Al-Ni enriched B2 phase + Cr-Fe-Co enriched A2 phase. It was micromorphology found that directional solidification could not only make the microstructures arranged regularly but also coarsen the grains. This has been attributed to the preferred grain orientation and lower cooling rate during directional solidification process. Compression testing showed that the compressive ductility of directionally solidified samples decreased obviously. The ultimate compressive strength of Al0.6CoCrFeNi HEA increased from 1 675 MPa to 1 903 MPa, but the strength of Al1.2CoCrFeNi HEA decreased from 2 183 MPa to 1 463 MPa. The difference in strength has been suggested to be the result of micropores in the matrix.

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The effect of bcc/fcc phase preference on magnetic properties of Al CrFeCoNi high entropy alloys

Intermetallics ◽

10.1016/j.intermet.2019.106672 ◽

2020 ◽

Vol 118 ◽

pp. 106672 ◽

Cited By ~ 3

Author(s):

J. Cieslak ◽

J. Tobola ◽

M. Reissner

Keyword(s):

Magnetic Properties ◽

High Entropy Alloys ◽

High Entropy ◽

Fcc Phase ◽

Phase Preference

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A Study on the Phase Formation and Magnetic Properties of FeNiCoCuM (M = Mo, Nb) High-Entropy Alloys Processed Through Powder Metallurgy

Metallurgical and Materials Transactions A ◽

10.1007/s11661-021-06137-4 ◽

2021 ◽

Vol 52 (3) ◽

pp. 1044-1058

Author(s):

P. Martin ◽

C. Salvo ◽

E. Pio ◽

G. Neves ◽

Henry A. Colorado ◽

...

Keyword(s):

Magnetic Properties ◽

Powder Metallurgy ◽

Phase Formation ◽

High Entropy Alloys ◽

High Entropy

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

Materials Letters ◽

10.1016/j.matlet.2021.129965 ◽

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

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

Metals ◽

10.3390/met11121907 ◽

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.

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