A Novel Soft‐Magnetic B2‐Based Multiprincipal‐Element Alloy with a Uniform Distribution of Coherent Body‐Centered‐Cubic Nanoprecipitates

Abstract

Multiprincipal‐element alloys (MPEAs), including high‐entropy alloys, are a new class of materials whose thermodynamical properties are mainly driven by configuration entropy, rather than enthalpy in the traditional alloys, especially at high temperatures. Herein, the design of a novel soft‐magnetic nonequiatomic, quaternary MPEA is described, via tuning its chemical composition to deliberately manipulate its microstructure, such that it contains ultrafine ferromagnetic body‐centered‐cubic (BCC) coherent nanoprecipitates (3–7 nm) uniformly distributed in a B2‐phase matrix. The new alloy Al1.5Co4Fe2Cr exhibits high saturation magnetization (MS = 135.3 emu g‐1), low coercivity (HC = 127.3 A m‐1), high Curie temperature (TC = 1061 K), and high electrical resistivity (ρ = 244 μΩ cm), promising for soft magnets. More importantly, these prominent soft‐magnetic properties are observed to be retained even after the alloy is thermally exposed at 873 K for 555 h, apparently attributable to the excellent stability of the coherent microstructure. The versatility of the magnetic properties of this new alloy is discussed in light of the microstructural change induced by tuning the chemical composition, and the enhanced performance of the alloy is compared directly with that of the traditional soft‐magnetic alloys. The perspective is also addressed to design high‐performance soft‐magnetic alloys for high‐temperature applications.

Order-Disorder Competitive Cooperation in Equiatomic 3d-Transition-Metal Quaternary Alloys: Phase Stability and Electronic Structure

“…Beyond 1277 K, the RSS phase shows a lower free energy of formation than Mn-D0 22 and becomes a stable phase in the high-temperature region. (11) and FeCoNiCu (15). In contrast, alloys with large VEC values and Cu as a constituent exhibit the RSS phases.…”

“…Although HEAs were originally applied to structural materials that required both strength and ductility, [2][3][4] their recent applications have been extended to other functional materials such as catalysis, [5][6][7] superconductors, [8] radiation resistance materials [9], and magnetic materials. [10,11] These extensions of their applications represent a new direction of materials design based on the fundamental and key concept of "highentropy." Along with this new direction, the comprehensive understanding of quantitative structure-property relationship (QSPR) is crucial for exploiting their potential applications.…”

“…A few ordered phases, such as Cr-L1 2 phase, show a narrow dispersion of formation free energy, while many ordered phases show a same wide dispersion as RSS phases. Interestingly, X-L1 2 (X = Cr and Mn) phases of CrMnNiCu (VEC ave = 8.50) in(8), CrFeNiCu (VEC ave = 8.75) in(10), MnFeCoCu (VEC ave = 8.75) in(11), CrCoNiCu (VEC ave = 9.0) in(12), MnFeNiCu (VEC ave = 9.0) in(13), and MnCoNiCu (VEC ave = 9.25) in(14) atFig. S-2 show a scatter distribution.…”

Design for Ti-Al-V-Mo-Nb alloys for laser additive manufacturing based on a cluster model and on their microstructure and properties

“…Hence, a novel alloy based on the cluster formula [(Mo 0.5 , Sn 0.5 )-Ti 13 Zr 1 ]Nb 1 presents the lowest Young's modulus (48 GPa) [18] . The cluster-plus-glueatom model has been proven to be useful for the composition design of the alloy [19,20] .…”

A mechanically strong and ductile soft magnet with ultralow coercivity

“…The theory of the grain size dependence of coercivity 7 shows its proportionality to the 6 th power of the grain size for the case of nanocrystalline materials, a relation that can be also applied to particles 8 . Current design of SMMs has thus focused on using small particles (<15 nm) 8,9 and grain sizes (<100 nm) [10][11][12] . According to magnetic strain theory, the coercivity depends on the energy required to displace domain walls to overcome lattice barriers [13][14][15] .…”