Face-centered Cubic Matrix Research Articles

Fine tuning in-sync the mechanical and magnetic properties of FeCoNiAl0.25Mn0.25 high-entropy alloy through cold rolling and annealing treatment

Abstract In this study, the mechanical and magnetic properties of FeCoNiAl0.25Mn0.25 high-entropy alloy (HEA) were investigated by subjecting as-cast samples to cold rolling and annealing at different temperatures for 1 h. The as-cast and cold rolled HEAs show a single-phase face-centered cubic (FCC) structure. The annealing temperature has a noteworthy influence on the phase composition and microstructure of the cold rolled HEA, and the microstructural evolution is described as follows: heterogeneous microstructure with a FCC matrix and body-centered cubic (BCC) precipitates (750 ℃ and 850 ℃) → recrystallized microstructure with FCC matrix and BCC precipitates (950 ℃) → coarse grains with a single FCC phase (1050 ℃). Though the HEA annealed at 1050 ℃ has the best ductility and lowest coercivity, the yield strength is very low. A good combination of ductility and strength is found in the sample annealed at 850 ℃ (CR+HEA-850), whose microstructure is comprised of BCC precipitates, recrystallized FCC equiaxed grains and a few FCC hard-deformed lamellae. The heterogeneous structure of the CR+HEA-850 resulted in a strong back stress, which contributes to its good mechanical properties. The high yield strength came from the grain refinement, dislocation strengthening, Orowan effect, and twin boundaries. Additionally, its soft magnetic properties are also appealing, showing high saturated magnetization (112.4 emu/g) and good coercivity (8.7 Oe). Compared with the HEAs on other conditions in this study and those previously reported, the CR+HEA-850 displays an interesting combination of magnetic and mechanical performance, which offers a strategy towards a new generation of multifunctional high-entropy alloys.

Thermal expansion-adjustable carbon-doped FeCoCrNiMn high-entropy alloys for electronic packaging

Application of an electronic packaging material is always limited by its established coefficient of thermal expansivity (CTE) and poor plastic working capacity. Here, we explored that a ductile high-entropy alloy (HEA) could achieve adjustable CTE values via decomposing at 500 °C. The carbon-doped equiatomic FeCoCrNiMn HEAs (0.8, 1.0, and 1.3 at% C) decomposed into B2, L10, M23C6 and σ phases during annealing. The adjustable CTE of the carbon-doped HEAs can be ascribed to the relatively low CTE values of the formed B2, L10, M23C6, and σ phases. The CTE value of a single face-centered cubic (FCC)-structured FeCoCrNiMn-1.3 at% C HEA is 16.7 × 10–6 °C−1, yet it can be continuously adjusted to 11.3 × 10–6 °C−1 when the FCC matrix is gradually decomposed into the B2, L10, M23C6, and σ phases. Furthermore, the decomposition rate and fractions of the B2, L10, M23C6, and σ phases can be controlled via changing carbon concentration and rolling reduction. More importantly, the CTE range of the 1.3C HEAs meets the requirements of electronic packaging. This work provides a way to design HEAs with desirable CTE for electronic industry via annealing at intermediate temperature.

Decomposition kinetics of carbon-doped FeCoCrNiMn high-entropy alloy at intermediate temperature

Abstract Phase decomposition kinetics and the corresponding mechanical properties of the severe cold-rolled (SCRed) carbon-doped (1.3 at.%) equimolar FeCoCrNiMn high-entropy alloy (HEA) after being annealed at 500 °C were investigated. This single face-centered cubic (FCC) solid-solution HEA decomposed to M23C6+L10, B2, and σ in chronological order. The formation kinetics of the L10, B2, and σ phases followed the Johnson−Mehl−Avrami− Kolmogorov (JMAK) equation. The yield strength of the HEA was 1520 MPa and increased to 1920 MPa after being annealed at 500 °C for 1 h, as a result of the formation of nanosized M23C6 and L10. Both strength and ductility decreased after 2 d of annealing due to the increase of volume fractions and the coarsening of the M23C6 and L10 precipitates. From 4 to 32 d, the hardness was found to increase, which is ascribed to the rapid formation of the B2 and σ phases. From 32 to 64 d, the hardness increased further to finally reach about HV 760, with the FCC matrix almost exhausted to form the M23C6, L10, B2, and σ phases. The results of this work may serve as a guide for the heat-treatment of carbon-doped HEAs.

A ductile high entropy alloy strengthened by nano sigma phase

A nanoscale sigma (σ) phase strengthened Co34.5Cr30Ni26.5Al5.4W3.6 (at, %) high entropy alloy was prepared and showed high strength and ductility. Dual phase microstructure that comprises face-centered cubic (FCC) matrix and nanoscale σ particles was obtained after thermomechanical procedures. The excellent ductility is attributed to its high strain hardening exponent FCC matrix that strongly favors uniform deformation and prevents crack propagation. The alloy shows an extremely high strain hardening rate and strength due to the interactions between the σ particles, deformation twins and dislocations. The design concept of “deformation twins + nano particles” should be considered for the design of additional double-high (strength and ductility) FCC HEAs in future work.

Effect of annealing on microstructure and mechanical properties of an ultrafine-structured Al-containing FeCoCrNiMn high-entropy alloy produced by severe cold rolling

Severe cold rolling (SCR) and annealing were applied to a face-centered cubic (FCC) Al0.3FeCoCrNiMn high entropy alloy. The crystal structure, microstructure, and mechanical properties of this SCRed Al-containing HEA were studied systematically. The coarse-grained alloy is substantially refined after SCR resulting in great improvement of the hardness and strength. With Al addition into the FeCoCrNiMn alloy, the thermal stability of this alloy is declined, and the precipitation of σ and B2 phases in the FCC matrix is greatly promoted. The microstructure evolution of the SCRed alloy during annealing can be divided into three stages: the combined precipitation of σ and B2 phases blow 1000 °C; the dissolution of σ phases and only B2 phase precipitates at 1000 °C; recovering to a single FCC phase at 1100 °C. The SCRed alloys annealed at 500–700 °C show a high strength but with a low ductility due to formation of a large number of σ and B2 phases. With increasing annealing temperature, the strength is gradually reduced that is attributed to grain growth of the matrix and dissolution of precipitates. In addition, these precipitates effectively suppress the grain growth of the matrix during annealing. A fully recrystallized and ultrafine-grained alloy with multiphase structure is obtained as the SCRed alloy annealing at 800 °C, which shows the YS, UTS and the elongation to failure of this alloy are 970 MPa, 1080 MPa and 8%, respectively. The high strength of this alloy is attributed to the grain refinement strengthening and precipitation strengthening.

Influence of non-magnetic Cu on enhancing the low temperature magnetic properties and Curie temperature of FeCoNiCrCu(x) high entropy alloys

The microstructure and magnetic properties of three face-centered cubic (FCC) FeCoNiCrCu(x) high entropy alloys (HEAs) (x = 0, 0.5, 1) are investigated. Interestingly, addition of the nonmagnetic element Cu to FeCoNiCr HEA is found to enhance exchange interactions and low temperature saturation magnetization. The paramagnetic to ferromagnetic Curie transition temperature increases from 85 K for FeCoNiCr to 118 K for FeCoNiCrCu. This is counterintuitive since Cu is nonmagnetic; however, atom probe tomography revealed Cu rich clusters containing 5 at% Ni and 1 at% each of Fe, Co, Cr, within FCC matrix, these clusters altered the matrix composition and consequently its magnetic properties.

Hierarchical Eutectoid Nano-lamellar Decomposition in an Al0.3CoFeNi Complex Concentrated Alloy

This paper reports a novel eutectoid nano-lamellar (FCC + L12)/(BCC + B2) microstructure that has been discovered in a relatively simple Al0.3CoFeNi high entropy alloy (HEA) or complex concentrated alloy (CCA). This novel eutectoid nano-lamellar microstructure presumably results from the complex interplay between Al-mediated lattice distortion (due to its larger atomic radius) in a face-centered cubic (FCC) CoFeNi solid solution, and a chemical ordering tendency leading to precipitation of ordered phases such as L12 and B2. This eutectoid microstructure is a result of solid-state decomposition of the FCC matrix and therefore distinct from the commonly reported eutectic microstructure in HEAs which results from solidification. This novel nano-lamellar microstructure exhibits a tensile yield strength of 1074 MPa with a reasonable ductility of 8%. The same alloy can be tuned to form a more damage-tolerant FCC + B2 microstructure, retaining high tensile yield stress (~900 MPa) with appreciable tensile ductility (>20%), via annealing at 700 °C. Such tunability of microstructures with dramatically different mechanical properties can be effectively engineered in the same CCA, by exploiting the complex interplay between ordering tendencies and lattice distortion.

Influence of Non-magnetic Cu on Enhancing the Low Temperature Magnetic Properties and Curie Temperature of FeCoNiCrCu(x) High Entropy Alloys

The microstructure and magnetic properties of three face-centered cubic (FCC) FeCoNiCrCu(x) high entropy alloys (HEAs) (x=0, 0.5, 1) are investigated. Interestingly, addition of the nonmagnetic element Cu to FeCoNiCr HEA is found to enhance exchange interactions and low temperature saturation magnetization. The paramagnetic to ferromagnetic Curie transition temperature increases from 85 K for FeCoNiCr to 118 K for FeCoNiCrCu. This is counterintuitive since Cu is nonmagnetic; however, atom probe tomography revealed Cu rich clusters containing 5 at% Ni and 1 at% each of Fe, Co, Cr, within FCC matrix, these clusters altered the matrix composition and consequently its magnetic properties.

Effects of Al and Ti Additions on Irradiation Behavior of FeMnNiCr Multi-Principal-Element Alloy

Two Co-free multi-principal-element alloys (MPEAs), viz. single-phase face-centered cubic (FCC) Fe30Ni30Mn30Cr10 and (Fe30Ni30Mn30Cr10)94Ti2Al4 (all in atomic percent) with FCC matrix containing Ni-Ti-Al enriched L12 (ordered FCC) secondary phase (γ′), have been developed and investigated. The alloys were ion irradiated at 300°C and 500°C to peak damage of 120 displacements per atom (dpa). Compared with the (Fe30Ni30Mn30Cr10)94Ti2Al4 alloy, in the Fe30Ni30Mn30Cr10 alloy, the dislocation loops were smaller, with a higher number density. The difference in loop size between the two MPEAs was attributed to the addition of Ti to the matrix, which was anticipated to lower the stacking fault energy and stabilize the faulted Frank loops. The γ′ phase showed good stability under irradiation, with no new γ′ precipitation or growth in existing precipitates. Both alloys showed similar irradiation-induced hardening at 300°C, but the (Fe30Ni30Mn30Cr10)94Ti2Al4 alloy exhibited lower irradiation-induced hardening at 500°C compared with the Fe30Ni30Mn30Cr10 alloy.

Precipitate behavior in nitrogen-containing CoCrNi medium-entropy alloys

The effect of nitrogen addition toward nitride precipitate formation and the corresponding behavior in a medium-entropy alloy system of N-CoCrNi was investigated. It was observed that the addition of N induced the formation of a Cr- and N-rich precipitate of Cr2N. Cr2N and the face-centered cubic (FCC) matrix in the N-CoCrNi system exhibited a Kikuchi orientation relation in the {111}γ//{0001}Cr2N plane and 〈110〉γ//〈11¯00〉Cr2N direction, where Cr2N was observed to be semi-coherent with the FCC matrix. The presence of Cr2N was also observed to contribute in the hindering of grain coarsening via Zener pinning pressure. The distribution of finer and higher fraction of Cr2N in the lower annealing temperatures of N-CoCrNi contributed more toward higher Zener pinning pressure compared to the coarser and lower fraction of Cr2N in the higher annealing temperatures, which subsequently affected grain growth during the annealing treatment.

The outstanding tensile strength of Ni-rich high entropy superalloy fabricated by powder metallurgical process

The present work reports the microstructure and tensile properties of a Ni-rich high-entropy superalloy (HESA; Ni46Co22Al12Cr8Fe8Ti3Mo1) having outstanding tensile properties, including yield strength of 1355 MPa and fracture elongation of 8.7%. Powder metallurgical (PM) processes were used to fabricate the present HESA with homogeneous and fine-grained microstructure. A large number of γʹ precipitates were homogeneously distributed in a face-centered cubic (FCC) matrix. By using PM processes, a nanoscale grain size was achieved, and ultrafine TiC and Al2O3 dispersoids were uniformly formed within the FCC matrix. The outstanding mechanical properties of the HESA were attributed to the combined effect of grain boundary strengthening, solid solution strengthening, precipitate formation and dispersion strengthening.

The effect of Al to high-temperature deformation mechanisms and processing maps of Al0.5CoCrFeMnNi high entropy alloy

The high-temperature deformation mechanism and processing maps of cast Al0.5CoCrFeMnNi that comprises face centered cubic (FCC) and body centered cubic (BCC) phases (where BCC phase is a minor phase) were studied at temperatures in the range of 1023–1323 K and at strain rates in the range of 10−3 to 101 s−1. During hot compressive deformation, the hard BCC phase provided nucleation sites for dynamically recrystallized (DRXed) grains in the soft FCC matrix through particle stimulated nucleation (PSN). The PSN-induced DRX occurred by continuous dynamic recrystallization (CDRX) and CDRX accelerated as temperature increased. Due to the effect of PSN, the fraction of DRXed grains was notably higher and the size of the DRXed grain size was considerably smaller in Al0.5CoCrFeMnNi than those in the equiatomic CoCrFeMnNi with a single FCC phase. The effect of the BCC phase on the fraction of DRXed grains was pronounced even at the high strain rate of 10 s-1 in the temperature range between 1173 and 1323 K, which is advantageous for the practical use of cast Al0.5CoCrFeMnNi in the hot-working industry. Solute drag creep appeared at low strain rates and at high temperatures as the rate-controlling deformation mechanism due to the presence of Al solutes in the FCC matrix phase. The activation energy for plastic flow associated with solute drag creep was estimated to be 251 kJ/mol. This value most likely represents the activation energy for the diffusivity of aluminum solutes in Al0.5CoCrFeMnNi. The solute drag creep behavior could be predicted by the Weertman model, suggesting that Al0.5CoCrFeMnNi behaves similar to a typical class I type solid solution metal alloy. By adding aluminum to CoCrFeMnNi, the hot workability can be greatly improved according to the processing maps. The power dissipation efficiency notably increases, and the flow instability regime decreases in size.

Deformation-driven bidirectional transformation promotes bulk nanostructure formation in a metastable interstitial high entropy alloy

We investigate the mechanisms of deformation-driven forward and reverse (bidirectional) martensitic transformation and the associated nanostructure formation in a metastable carbon-doped high entropy alloy (HEA) upon cold rolling. At thickness reductions below 14%, forward hexagonal-close packed (HCP) martensitic transformation prevails in the single face-centered cubic (FCC) matrix. Surprisingly, at the intersections of two crossing HCP lamellae, deformation-induced reverse transformation from the HCP martensite back to the FCC phase occurs. At higher thickness reductions around 26%–34%, multiple deformation kink bands develop, mainly on the pyramidal habit planes of the HCP martensite, among which reverted FCC phase is also observed resulting in a dual-phase nano-laminated structure. The deformation-induced reverted FCC phase regions exhibit a twin stacking sequence relative to the prior FCC matrix, which is related to the underlying dislocation reactions and rearrangement of the partial dislocations. At 67% thickness reduction, the deformation bands develop further into micro-shear bands consisting of nanosized (sub)grains. For rendering the dual-phase nanostructure back to single-phase FCC, 400 °C/10 min tempering is applied on a 34% cold-rolled specimen. The resulting nanostructure is characterized by nano-(sub)grains and nano-twins. It exhibits an excellent strength-ductility synergy (ultimate tensile strength 1.05 GPa at 35% total elongation) due to the improved work hardening enabled by both, FCC-HCP martensitic transformation in confined regions and mechanical twinning. With this, we show that bulk nanostructured alloys with bidirectional transformation can be designed by tuning the materials’ phase stability to their thermodynamic limits with the aim to trigger sequential athermal forward and reverse transformation under load.

Deformation-Driven Bidirectional Transformation Promotes Bulk Nanostructure Formation in a Metastable Interstitial High Entropy Alloy

We investigate the mechanisms of deformation-driven forward and reverse (bidirectional) martensitic transformation and the associated nanostructure formation in a metastable carbon-doped high entropy alloy (HEA) upon cold rolling. At thickness reductions below 14%, forward hexagonal-close packed (HCP) martensitic transformation prevails in the single face-centered cubic (FCC) matrix. Surprisingly, at the intersections of two crossing HCP lamellae, deformation-induced reverse transformation from the HCP martensite back to the FCC phase occurs. At higher thickness reductions around 26%-34%, multiple deformation kink bands develop, mainly on the pyramidal habit planes of the HCP martensite, among which reverted FCC phase is also observed resulting in a dual-phase nano-laminated structure. The deformation-induced reverted FCC phase regions exhibit a twin stacking sequence relative to the prior FCC matrix, which is related to the underlying dislocation reactions and rearrangement of the partial dislocations. At 67% thickness reduction, the deformation bands develop further into micro-shear bands consisting of nanosized (sub)grains. For rendering the dual-phase nanostructure back to single-phase FCC, 400 °C/10 min tempering is applied on a 34% cold-rolled specimen. The resulting nanostructure is characterized by nano-(sub)grains and nano-twins. It exhibits an excellent strength-ductility synergy (ultimate tensile strength 1.05 GPa at 35% total elongation) due to the improved work hardening enabled by both, FCC-HCP martensitic transformation in confined regions and mechanical twinning. With this we show that bulk nanostructured alloys with bidirectional transformation can be designed by tuning the materials' phase stability to their thermodynamic limits with the aim to trigger sequential athermal forward and reverse transformation under load.

On the mechanism of extraordinary strain hardening in an interstitial high-entropy alloy under cryogenic conditions

We investigate the cryogenic deformation response and underlying mechanisms of a carbon-doped interstitial high-entropy alloy (iHEA) with a nominal composition of Fe49.5Mn30Co10Cr10C0.5 (at. %). Extraordinary strain hardening of the iHEA at 77 K leads to a substantial increase in ultimate tensile strength (∼1300 MPa) with excellent ductility (∼50%) compared to that at room temperature. Prior to loading, iHEAs with coarse (∼100 μm) and fine (∼6 μm) grain sizes show nearly single face-centered cubic (FCC) structure, while the fraction of hexagonal close-packed (HCP) phase reaches up to ∼70% in the cryogenically tensile-fractured iHEAs. Such an unusually high fraction of deformation-induced phase transformation and the associated plasticity (TRIP effect) is caused by the strong driving force supported by the reduced stacking fault energy and increased flow stress at 77 K. The transformation mechanism from the FCC matrix to the HCP phase is revealed by transmission electron microscopy (TEM) observations. In addition to the deformation-induced phase transformation, stacking faults and dislocation slip contribute to the deformation of the FCC matrix phase at low strains and of the HCP phase at medium and large strains, suggesting dynamic strain partitioning among these two phases. The combination of TRIP and dynamic strain partitioning explain the striking strain hardening capability and resulting excellent combination of strength and ductility of iHEAs under cryogenic conditions. The current investigation thus offers guidance for the design of high-performance HEAs for cryogenic applications.

Novel NiAl-strengthened high entropy alloys with balanced tensile strength and ductility

A single phase, face-centered-cubic (FCC) Al0.3CoCrFeNi high entropy alloy usually has low yield strength. Here, a precipitate-strengthened Al0.3CoCrFeNi has been developed, exhibiting enhanced yield strength while retaining good ductility, which is attributed to a novel microstructure comprising a finely distributed, needle-like B2 phase within the grains of the FCC matrix and a granular σ phase along the grain boundaries. Such a microstructure was obtained by a two-step heat treatment of an as-cast Al0.3CoCrFeNi, whose parameters were determined by integrating CALPHAD-based thermodynamic calculations with microstructural characterization by atom probe tomography. In situ neutron diffraction, in conjunction with crystal-plasticity finite-element simulations, has revealed the strengthening effect owing to the load partitioning between the constituent phases. This work has important implications for understanding phase stability and deformation mechanisms in multi-principal component alloys, and paves the way for developing novel microstructures in complex alloys using correlative techniques.

Strain Rate Sensitivity of a TRIP-Assisted Dual-Phase High-Entropy Alloy

Dual-phase high-entropy alloys (DP-HEAs) with transformation induced plasticity (TRIP) have an excellent strength-ductility combination. To reveal their strain-rate sensitivity and hence further understand the corresponding deformation mechanisms, we investigated the tensile behavior and microstructural evolution of a typical TRIP-DP-HEA (Fe50Mn30Co10Cr10, at. %) under different strain rates (i.e., 5 × 10-3 s-1, 1 × 10-3 s-1, 5 × 10-4 s-1 and 1 × 10-4 s-1) at room temperature. The strain rate range was confined to this regime in order to apply the digital image correlation technique for probing the local strain evolution during tensile deformation at high resolution and to correlate it to the microstructure evolution. Grain size effects of the face-centered cubic (FCC) matrix and the volume fractions of the hexagonal-close packed (HCP) phase prior to deformation were also considered. The results show that within the explored strain rate regime the TRIP-DP-HEA has a fairly low strain rate sensitivity parameter within the range from 0.004 to 0.04, which is significantly lower than that of DP and TRIP steels. Samples with varying grain sizes (e.g., ~2.8 μm and ~38 μm) and starting HCP phase fractions (e.g., ~25% and ~72%) at different strain rates show similar deformation mechanisms, i.e., dislocation plasticity and strain-induced transformation from the FCC matrix to the HCP phase. The low strain rate sensitivity is attributed to the observed dominant displacive transformation mechanism. Also, the coarse-grained alloy samples with a very high starting HCP phase fraction (~72%) prior to deformation show very good ductility with a total elongation of ~60%, suggesting that both, the initial and the transformed HCP phase in the TRIP-DP-HEA are ductile and deform further via dislocation slip at the different strain rates which were probed.

Effect of annealing heat treatment on microstructural evolution and tensile behavior of Al0.5CoCrFeMnNi high-entropy alloy

In this work, the mechanical characteristics and microstructural evolution of Al0.5CoCrFeMnNi high-entropy alloy (HEA) were studied after annealing at various temperatures (1000, 1100, and 1200 °C). X-ray diffraction, scanning electron microscopy, and energy dispersive spectroscopy analyses were performed to reveal the phase and microstructural variations. The mechanical properties related to different microstructures of the alloy were characterized using tensile testing with digital image correlation. Annealing at lower temperatures led to a higher fraction of B2 phase and finer grain size of FCC (face-centered cubic) phase. A good combination of strength and ductility in this alloy was attributed to the ductile FCC matrix and hard secondary B2 phase. The alloy showed the active evolution of deformation twinning due to the low stacking fault energy when Al was added to CoCrFeMnNi to make the HEA. However, for alloy annealed at lower temperatures, twinning activity was suppressed by the smaller size of grains and depletion of Al content in the FCC matrix. The correlation between the microstructure and mechanical properties was also explored using a simple composite model.

Elastic moduli and thermal expansion coefficients of medium-entropy subsystems of the CrMnFeCoNi high-entropy alloy

Elastic moduli of a set of equiatomic alloys (CrFeCoNi, CrCoNi, CrFeNi, FeCoNi, MnCoNi, MnFeNi, and CoNi), which are medium-entropy subsystems of the CrMnFeCoNi high-entropy alloy were determined as a function of temperature over the range 293 K–1000 K. Thermal expansion coefficients were determined for these alloys over the temperature range 100 K–673 K. All alloys were single-phase and had the face-centered cubic (FCC) crystal structure, except CrFeNi which is a two-phase alloy containing a small amount of body-centered cubic (BCC) precipitates in a FCC matrix. The temperature dependences of thermal expansion coefficients and elastic moduli obtained here are useful for quantifying fundamental aspects such as solid solution strengthening, and for structural analysis/design. Using the above results, the yield strengths reported in literature for these alloys were normalized by their shear moduli to reveal the influence of shear modulus on solid solution strengthening.

Effect of aluminum element on microstructure evolution and properties of multicomponent Al-Co-Cr-Cu-Fe-Ni nanoparticles

A series of multicomponent Al-Co-Cr-Cu-Fe-Ni nanoparticles with different aluminum contents were prepared by modified arc-discharge method. The effect of Al element on crystal structure, microstructure, corrosion resistance, and soft magnetic properties were investigated. The evolution of phase structure changes from the initial single Cu-rich face-centered cubic (FCC) phase to FCC + M3Al-type L12 phases, and eventually to FCC + body-centered cubic (BCC) phases with increasing Al contents. Moreover, the as-prepared nanoparticles are spherical with an average size of about 110–180 nm, and the chemical compositions of the nanoparticles greatly deviate from the nominal compositions of the targets. Furthermore, the corrosion resistance deteriorates and the soft magnetic behavior increases, when the structure changes from the simple FCC phase to a mixture of FCC and BCC phase. The emergence of M3Al-type L12 phase in the FCC matrix brings the best corrosion resistance and the lowest soft magnetic property. The multicomponent nanoparticles with controllable structure and composition can be easily prepared by this method for particular applications.