Fe-based Metallic Glass Research Articles

Densification and heterogeneity enhancement of Fe-based metallic glass under local plastic flow

The atomic-scale structure and concomitant mechanical property evolution of a ribbon-shaped Fe<sub>78</sub>Si<sub>9</sub>B<sub>13</sub> metallic glass after local plastic flow are investigated. By using abrasive papers as a medium to transport the pressure, the equivalent pressure on the ribbon surface is sufficiently magnified. Multiple shear bands pervading along their surface are generated simultaneously after deformation. The densification processes triggered by the cooperative atomic rearrangements in the short and medium-range are revealed by analyzing the synchrotron diffraction patterns in reciprocal space and real space. Meanwhile, the local plastic flow enhances the structural heterogeneity. In contrast to the strain-softening under uniaxial loading, these structural changes contribute to the improvement of resistance to subsequent deformation. As a result, the Vickers hardness of the deformed Fe<sub>78</sub>Si<sub>9</sub>B<sub>13</sub> metallic glass increases compared with the undeformed sample, manifesting a local strain-hardening behavior.

Remarkably enhanced Fenton-like catalytic activity and recyclability of Fe-based metallic glass by alternating magnetic field: mechanisms and industrial applications

Fenton-like processes by metallic glass catalysts under alternating magnetic field present a new strategy for the ever-growing water pollution problems.

Synergistic Improvement on Strength and Plasticity for Spherical Fe-Based Metallic Glass Particles Reinforced Mg-Based Composites

Synergistic Improvement on Strength and Plasticity for Spherical Fe-Based Metallic Glass Particles Reinforced Mg-Based Composites

Removal of acid orange II azo dyes using Fe-based metallic glass catalysts by Fenton-like process

Removal of acid orange II azo dyes using Fe-based metallic glass catalysts by Fenton-like process

Synergistic Evolution Mechanism of the Atomic/Nano Scale Structural Heterogeneity of Fe-Based Metallic Glasses at Relaxation and the Effect on Magnetic Properties

Synergistic Evolution Mechanism of the Atomic/Nano Scale Structural Heterogeneity of Fe-Based Metallic Glasses at Relaxation and the Effect on Magnetic Properties

Selective Laser Melting of Fe-Based Metallic Glasses with Different Degree of Plasticity

Selective Laser Melting of Fe-Based Metallic Glasses with Different Degree of Plasticity

Selective laser melting of an Mg/Metallic Glass hybrid for significantly improving chemical and mechanical performances

Pure magnesium (Mg) is widely used as biomedical material, but its degradation rate is often too high and problematic to clinic applications. In this study, selective laser melting (SLM) was used to prepare an Fe-based metallic glass surface on a pure Mg substrate, forming a hybrid material to explore the advantage associated with such designed structure. It was found that the corrosion resistance was significantly improved with the hybrid material (from 0.89 ± 0.1 mm/a to 0.11 ± 0.03 mm/a in simulated body fluid), along with much increased hardness from 0.46 GPa to 14.3 GPa. The metallic glass surface was shown to retain its amorphous nature after the SLM processing. The molten pool formed by the applied laser beam resulted in a good mechanically interlocked bonding between the metallic glass layer and the Mg matrix. It was further revealed that the metallic glass surface had better wetting property than the Mg substrate, explaining why the MG-63 cells had good adhesion to it. The cell toxicity test was followed under the in vitro condition, indicating no toxicity in the metallic glass part. The results provide a feasible way to develop advanced Mg materials for biomedical applications via the capable SLM technology and via the suggested hybrid material.

Fabrication of Fe-based metallic glass reinforced FeCoNiCrMn high-entropy alloy through additive manufacturing: mechanical property enhancement and corrosion resistance improvement

In recent years, high entropy alloys (HEA) receive extensive attention for their excellent mechanical performance. In this paper, the FeCoNiCrMn high-entropy alloy reinforced material is produced by laser powder bed fusion (LPBF). The excellent tensile performance can be achieved through many strengthening mechanisms, e.g., solution strengthening, dislocation strengthening, fine-grain refinement, and dispersion strengthening. The reinforced material with additive Fe-based metallic glass shows a yield strength of 675 MPa, 29.8% higher than FeCoNiCrMn (520 MPa), and an average hardness of 241.9 HV, 12.7% higher than FeCoNiCrMn (214.6 HV). Meanwhile, the plasticity of the reinforced material is maintained at a good level. In comparison with FeCoNiCrMn, the corrosion current density is reduced by 18.9%, and the corrosion resistance is significantly improved. The high strength and corrosion resistance are achieved by the addition of Fe-based metallic glass, which provides a feasible approach for the preparation of HEA with enhanced mechanical properties in the future.

Composition design and properties characterization for FeSiBCuC metallic glasses with large plasticity

Fe-based metallic glasses have low magnetic induction and inferior plasticity because of inevitable doping of non-magnetic constituents. The study proposes an innovative composition design strategy considering the nature of elements, binary eutectic, atomic configuration, and mixing entropy in the alloy system. A novel composition of Fe78.9B11.8Si7.6C1Cu0.7 was adopted, adding a total of only 8.3 wt% non-magnetic elements. The critical size of Fe78.9B11.8Si7.6C1Cu0.7 bulk metallic glass was ~1 mm, and an ultra-thick ribbon of ~150 µm was obtained by twin-roll strip casting. Excellent soft magnetic properties with high saturation magnetization (Bs) of 1.68 T and low coercivity (Hc) of 7.1 A/m outperformed current conventional counterpart. Meanwhile, the high breaking strength of 2654 MPa and distinctive plastic strain of 2%, normally less than 0.5% in most Fe-based metallic glasses, was demonstrated in Fe78.9B11.8Si7.6C1Cu0.7 bulk metallic glass. This novel alloy composition and design strategy is expected to facilitate the development of next-generation magnetic materials.

Bimetal printing of high entropy alloy/metallic glass by laser powder bed fusion additive manufacturing

As metallic materials with distinctive microstructures and properties, high entropy alloys (HEAs) and metallic glasses (MGs) have their respective advantages. In this study, using laser powder bed (LPBF) additive manufacturing (AM), bimetal printing between a typical quinary HEA (CoCrFeMnNi) and an Fe-based MG has been realized, which inherits properties of both materials. As a result, the bulk material consisting of both alloys presents a significantly high hardness (from ∼251 HV to ∼1210 HV) and corrosion resistance (from ∼0.967 mm/year to ∼0.765 mm/year) resulted from the printed MG and a good combination of strength and ductility resulted from the printed HEA. Analytical means including transmission electron microscopy and electron back-scattered diffraction have been used to detail the microstructure, particularly the HEA/MG interface that is essential to forming a good interlocking bonding. The study demonstrates the capability of LPBF bimetal printing in developing advanced materials particularly having HEAs and MGs involved.

Nanosecond pulsed laser-induced formation of nanopattern on Fe-based metallic glass surface

Fe-based metallic glasses (MGs) have attracted much attention because of their cheap raw materials, outstanding soft magnetic properties and superior catalytic activity. Meanwhile, the fabrication of micro/nano-structures on its surface could further improve its functional properties. In this study, it was attempted to fabricate micro/nano-structures on a Fe-based MG (Fe52Cr13Mo12C15B6Er2, in at. %) surface by nanosecond pulsed laser irradiation technology. The surface characteristics and microstructural evolution of Fe-based MG were investigated. The experimental results showed that under different laser fluences, the laser-irradiated areas exhibited distinguished microstructures, i.e., nanoparticles, the network nanostructures or a combination of these two microstructures. Furthermore, oxygen and erbium were enriched inside the network nanostructures. By analyzing the microstructural evolution, formation mechanisms of the nanoparticles and the network nanostructures were discussed. The nanoparticles were actually caused by laser-induced element enrichment (i.e. amorphous erbium oxide) and the mismatch of its wettability with the substrate; the formation of the network nanostructures was attributed to the diffusion and connection of nanoparticles under the combined influence of recoil pressure and surface topography.

Developing an Economical Wear and Corrosion Resistant Fe-Based Metallic Glass Composite Coating by Plasma and HVOF Spraying

Developing an Economical Wear and Corrosion Resistant Fe-Based Metallic Glass Composite Coating by Plasma and HVOF Spraying

Controlling devitrification in the FeSiB system without alloying additions

Efficient electric machines require soft magnetic materials with superior properties, motivating research on the processing-structure-response correlation in Fe-based metallic glass systems. Here, significant differences in the primary devitrification process and the resulting microstructure of amorphous metallic Fe79Si11B10 alloys synthesized into two different forms by different rapid solidification methods are confirmed. Melt-spun ribbons and water-quenched microwires were investigated with calorimetric, structural, and magnetic probes. It is found that the primary devitrification process of the ribbons occurs at a higher temperature (by 80 K) with a faster exothermic heat release relative to that of the quenched microwires, despite their common chemical composition and fully devitrified structural state. Analysis of the primary devitrification reveals that the ribbons exhibit a ∼70% higher effective activation energy and a ∼110% larger value of Avrami exponent relative to those characterizing the microwires, indicating different devitrification routes taken by these two types of material. In specific, the ribbons crystallize via a continuous nucleation process that partly relies on pre-existing surface nuclei, with an interface-controlled growth mechanism. In contrast, the quenched microwires devitrify solely from pre-existing nuclei, with diffusion-controlled growth. These differences are attributed to unique quenched-in structures that are created by the specific rapid solidification conditions. These results suggest approaches to control the microstructure in FeSiB compositions without the need for non-magnetic alloying additions.

Influence of the microstructure on mechanical properties of SLM additive manufacturing Fe-based bulk metallic glasses

Fe-based bulk metallic glass (BMG)(FeCrMoWMnSiBC) was produced by selective laser melting (SLM) successfully in this study. The best parameters were determined through extensive experiments. The relative density (95%) and amorphous rate (95.47%) samples were obtained by this parameter. The analysis of the microstructure reveals that the crystalline phases in the heat affected zone (HAZ) are mainly α-Fe and M23(CB)6 phases, and co-exist with the amorphous phases. The Heat treatment is employed to study the crystallization behavior of amorphous phases. The α-Fe phase, as the primary phase, grows into a submicron crystal phase under the action of multiple thermal cycles. Nanoindentation test results show that the hardness of the amorphous phase is higher than that of the nano-grain region, and the hardness of the nanocrystalline region is higher than that of the submicron-grain region. The free volume content is different and the amorphous phase is not uniform due to the complex thermal cycle. The maximum hardness occurs in the amorphous phase with 22.6 GPa.

AlCoCrFeNi high entropy alloy fabricated via selective laser melting reinforced by Fe-based metallic glass

The 5% Fe-based amorphous reinforced AlCoCrFeNi high-entropy alloy (HEA) specimens were prepared by selective laser melting (SLM) technique. The mixed of Fe-based amorphous reduces the grain diameter and eliminates the presence of texture. Meanwhile, the anisotropy of the specimen was reduced. The addition of Fe-based amorphous causes the precipitation of FCC phase in the body-centered cubic (BCC) matrix, and the face-centered cubic (FCC) phase is uniformly distributed at the grain boundaries. The presence of FCC phase significantly reduces the internal stress of the specimen. The elements in the amorphous alloy solidly dissolve into the BCC matrix during the printing process, further strengthening the BCC matrix. The residual amorphous and nanocrystalline phases also result in a significant improvement in the performance of the specimen.

Fe-based bulk metallic glass with unprecedented plasticity at room temperature

Fe-based bulk metallic glasses (BMGs) have attracted significant attention due to their excellent soft magnetic properties and ultrahigh strength, but their brittleness limits their applications. Here, we report a Fe74Mo6P13C7 BMG with a diameter of 1.0 mm, which can be bent without fracturing and exhibits unprecedented plasticity (∼25%) at room temperature. We propose here the clusters in that Fe74Mo6P13C7 BMG are mainly linked by metal-metal bonds and account for the observed plasticity. This work demonstrates that the plasticity of Fe-based BMGs can be designed and improved obviously, and it opens up a possible pathway for manufacturing dispersion-strengthened glasses with high strength and/or plasticity.

Correction to: Engineering of Novel Fe-Based Bulk Metallic Glasses Using a Machine Learning-Based Approach

Correction to: Engineering of Novel Fe-Based Bulk Metallic Glasses Using a Machine Learning-Based Approach

Microstructure and performance of novel ductile FeNi-based metallic glasses

Fe-based bulk metallic glasses (BMGs) are of significant interest because of their superior magnetic and mechanical properties, but the plastic strain deficiency at room temperature restricts their application. In the present study, the effect of Ni content on thermal stability, soft magnetic properties and compressive plastic deformation was investigated in Fe80−xNixP12B4.9Si2.5Cu0.6 (x = 0, 3, 6, 9, 12, 15) BMGs. We discovered that the Ni-bearing BMGs exhibit strong GFA, good soft magnetic and mechanical properties, and high Tc, while the excessive Ni addition causes performance deterioration. The Fe71Ni9P12B4.9Si2.5Cu0.6 bulk glass exhibits high strength of about 3000 MPa and elevated plastic strain of 5.1%, together with high saturation magnetic induction of 1.51 T and low coercivity of 1.8 A/m. The Curie temperature up to 636 K was an intriguing finding. X-ray photoelectron spectroscopy results suggest that the brittle-ductile transition comes from the more s-like bonds between clusters because of the Ni addition. In terms of the inherent elastic nature, we consider that the high Poisson's ratio and the low G/K ratio of Ni lead to a large effective volume of the shear transition zone, which corresponds to the nucleation of shear bands. The significant compressive plastic behavior, large GFA and good soft magnetic properties indicated that the current Fe-based BMGs are promising for structural and magnetic functional applications.

Explicit expressions of the saturation flux density and thermal stability in Fe-based metallic glasses based on Lasso regression

Fe-based soft magnetic metallic glasses (MGs) have great potential for a wide variety of applications due to their low material cost and excellent soft magnetic properties. At present, a satisfactory combination of the saturation flux density (Bs) and thermal stability (Tx) in the above-mentioned MGs is of great challenge if the conventional trial-and-error method is adopted. In order to explore explicit expressions for predicting Bs and Tx of Fe-based soft magnetic MGs instead of implicit and unexplained machine learning (ML) models, herein, Lasso regression approach was employed and the predictive performance of the developed explicit expressions based on different input descriptors were analyzed. The obtained results show that there exists a highly linear relationship among composition, structure and property in Fe-based MGs. The studied explicit expressions of Bs and Tx exhibit good prediction efficiency with the high R2 scores of 0.952 and 0.968, respectively, which are both superior to the previously reported corresponding R2 values in the literature. This work suggests that Lasso regression possesses a great potential for assessing the quantitative composition-structure-property relationship, and thus might provide some hints to discover new Fe-based soft magnetic MGs.

Regular Nanowire Formation on Fe-Based Metal Glass by Manipulation of Surface Waves

We report the formation of a sole long nanowire structure and the regular nanowire arrays inside a groove on the surface of Fe-based metallic glass upon irradiation of two temporally delayed femtosecond lasers with the identical linear polarization parallel and perpendicular to the groove, respectively. The regular structure formation can be well observed within the delay time of 20 ps for a given total laser fluence of F = 30 mJ/cm2 and within a total laser fluence range of F = 30–42 mJ/cm2 for a given delay time of 5 ps. The structural features, including the unit width and distribution period, are measured on a one-hundred nanometer scale, much less than the incident laser wavelength of 800 nm. The degree of structure regularity sharply contrasts with traditional observations. To comprehensively understand such phenomena, we propose a new physical model by considering the spin angular momentum of surface plasmon and its enhanced inhomogeneous magnetization for the ferromagnetic metal. Therefore, an intensive TE polarized magnetic surface wave is excited to result in the nanometer-scaled energy fringes and the ablative troughs. The theory is further verified by the observation of nanowire structure disappearance at the larger time delays of two laser pulses.