Fe-based Composites Research Articles

Production of (B4C+FeTi) reinforced and Fe based composites by mechanical alloying

Abstract In this study, the microstructure and mechanical performance of Fe-based composites reinforced by FeTi+B4C at various ratios were determined. The study was based on the production of Fe based nano carbide and boride (B4C, Fe2B, Fe7C3, TiB2) reinforced composites. Mechanical alloying technique was chosen to reduce the reinforcement material to nano size and distribute it homogeneously. Sintering temperature was used as 1,100 °C and sintering time as 2 h. The reionforcement “FeTi+B4C” ratio was raised up to 15 wt.%. The microstructure and phases of the composite samples were descrived by scanning electron microscopy, energy dispersive spectroscopy, X-RD analysis and hardness. The concentration of voids and the stiffness changes of the samples were determined. The size of TiC and TiB2 particles reduced significantly with the rise in B4C ratio. Since the hardness of TiB2 was less than that of the B4C matrix, the hardness reduced with increasing TiB2 ratio.

Enhancements of magnetic properties and compacted density for Fe-based amorphous soft magnetic composites via hot compacting under an ultra-low pressure

Amorphous FeSiBCCr soft magnetic composites (FeSiBCCr-SMCs) with high compacted density (ρc) and excellent magnetic properties has been successfully hot-compacted under an ultra-low pressure of 160 MPa. The thermoplastic deformation of amorphous powders within the supercooled liquid region can give rise to the increase of ρc and the reduction of non-magnetic pores fraction for the SMCs. This situation is conductive to the decrease in resistance of domain wall motion during magnetization process of SMCs, and finally contributes to the improvement of SMCs’ soft magnetic properties. Under the recommended conditions with the compaction temperature (Tc) of 475 ℃, the pressure holding time (th) of 6 min, and the molding pressure (Pm) of 160 MPa, the FeSiBCCr-SMCs’ ρc increases by 28.8 % to 6.53 g/cm3, the corresponding effective permeability (μe) increases by 3.39 times to 73.1, while its total core loss (Pcv) reduces by 57.4 % to 275.3 kW/m3 at 100 kHz, 0.05 T compared with those of the SMCs prepared at Pm=600 MPa, Tc=25 ℃.

Fe-based amorphous soft magnetic composites with excellent magnetic properties fabricated via low-pressure hot compacting

FePBNbCr amorphous soft magnetic composites (SMCs) with high compaction density (ρc) and commendable magnetic properties were successfully fabricated via low-pressure hot-compacting at 160 MPa. Due to the thermoplastic properties of amorphous powders in supercooled liquid region (ΔTx), the hot-compacting in the ΔTx is conducive to the increase of ρc for the amorphous SMCs, thereby improving the corresponding soft magnetic properties via reducing the number of pinning sites. Compared with these of the cold-compacted amorphous SMCs at 600 MPa, the ρc increases by 20.3 % to 6.04 g/cm3, the effective permeability increases by 5.26 times to 95.3, while the corresponding total core loss decreases 74.5 % to 154.4 kW/m3 (100 kHz, 0.05 T) for the amorphous SMCs hot-compacted at 495 °C with a pressure holding time of 6 min. These results indicate that the low-pressure hot compacting is an effective measure to further improve soft magnetic properties of the amorphous SMCs for rapidly adapting to the development needs of high-frequency and miniaturization of electronic devices.

Effects of Ni–Cr–Mo–Si–B prealloy additives on the properties of Fe-based diamond composites

In this study, Fe-based diamond composites with various Ni–Cr–Mo–Si–B prealloy additives were prepared using hot-press sintering, and the effects of the Ni–Cr–Mo–Si–B content on the relative density, bending strength, Rockwell hardness, and frictional wear properties of the Fe–Cu–Co–Sn matrix were investigated. Additionally, the effect of the composition of the Ni–Cr–Mo–Si–B additives on the interface between the matrix and diamond was studied. The Ni and Cr in the additives facilitated a tight bonding interface without notable gaps between the diamond and Fe–Cu–Co–Sn matrix. Considering the overall performance of the materials, the optimal addition of Ni–Cr–Mo–Si–B was determined to be 10 %, which resulted in notably improved comprehensive performance indicators of the Fe-based diamond composite materials. For example, diamond drill bits made with this formulation exhibited a wear ratio of 1600 mm/g and a penetration rate of 29.21 mm/min, representing increases of 29 % and 44.96 %, respectively, compared to those of drill bits without Ni–Cr–Mo–Si–B additives. Developing high-performance diamond drill bits with increased ROP and extended service lives to enhanced performance, efficiency, and cost-effectiveness in drilling operations across different industries, ranging from mining and construction to oil and gas exploration.

Ultra-low core loss and high permeability Fe-based amorphous soft magnetic composites with ultra-fine FeNi additives

Ultra-low core loss and high permeability Fe-based amorphous soft magnetic composites with ultra-fine FeNi additives

Interdiffusion mechanism of hybrid interfacial layers for enhanced electrical resistivity and ultralow loss in Fe-based nanocrystalline soft magnetic composites

Soft magnetic composites (SMCs) composed of ferromagnetic particles and insulating binder are highly desired in energy-saving and high-efficiency devices for their high electrical resistivity and softer saturation characteristics. However, traditional insulation coatings are facing thermal instability, inhomogeneous distribution, and magnetic dilution, presenting a major challenge for the trade-off relationship between power loss and permeability. Here, the phosphate-coated FeSiBCuNb/SiO2 SMC is successfully fabricated by a unique interdiffusion effect in hybrid interfacial layers, which shows a combination of ultralow power loss of 135.8 kW/m3 (50 kHz/100 mT), high effective permeability of 80.6, and good temperature stability. The interdiffusion behavior between Si/O and Fe/P/O elements promotes the formation of ultrathin, uniform, and multilayer interface structure, which alleviates the magnetic dilution. Penetrating oxidation at the edge interface and elements interdiffusion effect contribute to a higher electrical resistivity induced by hot isostatic pressing with rapid quenching, leading to a low eddy current loss. Synergistic effect of isostatic pressures and rapid quenching facilitates the formation of high-density Cu clusters corresponding to ultrafine microstructure, which is beneficial for low coercivity and low hysteresis loss. This study involves the interdiffusion mechanism of hybrid interfacial layers and nanocrystalline behavior, providing a new strategy for the next-generation of high-performance SMCs.

Preparation and Performance Study of SiC-Reinforced Fe-Based Wear-Resistant Composite Grinding Media.

During industrial and laboratory processes involving material grinding, the grinding media endure prolonged high-collision and friction environments, resulting in substantial wear. Consequently, this study adopts the hot-pressing sintering technique in powder metallurgy to prepare SiC-reinforced Fe-based wear-resistant composite grinding media, aiming to increase wear performance. For this purpose, Fe with 10 wt% SiC powders were milled for the fabrication of the composite. Then, sintering was performed by hot press at 1100 °C in a furnace. Scanning electron microscopy (SEM) and X-ray diffraction were employed to investigate the microstructures and phase of SiC-reinforced Fe-based matrix composite. Subsequently, comparative performance evaluations of the newly developed grinding media and traditional chromium-based media were conducted in terms of wear rate and grinding efficiency. The wear resistance tests revealed that the SiC-reinforced composite media displayed significantly superior wear resistance across various abrasives compared to the chromium-containing alternatives. Specifically, the composite media achieved a wear rate reduction of 2.9 times against standard sand over 1 h, and 2.3 and 2.4 times against sandstone and iron slag, respectively. Moreover, extended grinding for 3 hours further enhanced these reductions to 3.1, 2.4, and 2.7 times, respectively. Additionally, efficiency assessments indicated that at a 1:1 material ratio, the composite media outperformed the chromium-containing media in grinding efficiency by 7.5%, 12.5%, and 10.3% for standard sand, sandstone, and iron slag, respectively. Further increasing the material ratio to 3:1 resulted in efficiency improvements of 7.4%, 17.5%, and 11.3%, correspondingly.

Comparative Study of Microstructure and Phase Composition of Amorphous-Nanocrystalline Fe-Based Composite Material Produced by Laser Powder Bed Fusion in Argon and Helium Atmosphere.

Laser powder bed fusion (LPBF) is a prospective and promising technique of additive manufacturing of which there is a growing interest for the development and production of Fe-based bulk metallic glasses and amorphous-nanocrystalline composites. Many factors affect the quality and properties of the resulting material, and these factors are being actively investigated by many researchers, however, the factor of the inert gas atmosphere used in the process remains virtually unexplored for Fe-based metallic glasses and composites at this time. Here, we present the results of producing amorphous-nanocrystalline composites from amorphous Fe-based powder via LPBF using argon and helium atmospheres. The analysis of the microstructures and phase compositions demonstrated that using helium as an inert gas in the LPBF resulted in a nearly three-fold increase in the amorphization degree of the material. Additionally, it had a beneficial impact on phase composition and structure in a heat-affected zone. The received results may help to develop approaches to control and improve the structural-phase state of amorphous-nanocrystalline compositional materials obtained via LPBF.

Unraveling the reaction activity of Fe-based compounds toward potassium-ion storage

Iron-based compounds have been extensively applied as anode materials for alkali-ion batteries. Nevertheless, how the intrinsic properties of Fe-based compounds affect their alkali-ion storage behavior still remain blurry, hampering the rational structure design of Fe-based anodes for superior performance. Herein, the reaction activities of various Fe-based compounds (e.g., FeS2, FeSe2, and FeP) toward K/Na/Li-ion storage are studied by rationally encapsulating Fe-compounds into hollow carbon boxes with an identical multi-yolk-shell structure. For potassium storage, FeSe2@C composite manifests the best battery performance with high capacity, superior rate capability, and excellent cycling behavior. FeS2@C exhibits high capacity, but with poor cycling retention and inferior rate capability. FeP@C shows the lowest capacity and poorest rate capability. As disclosed by density functional theory calculation and kinetics analysis, the superior potassium storage behavior of FeSe2@C is due to the high electrical conductivity and proper K+ diffusion ability of FeSe2, as well as its excellent pseudocapacitive behavior. The weak electron conductivity of FeS2 is responsible for its poor rate performance, and the large K+ diffusion barrier of FeP leads to its low reaction activity toward potassium-ion storage. Moreover, FeSe2@C also displays best rate capability among these Fe-based composites for both sodium and lithium storage.

Structure, soft magnetic properties of Fe-based magnetic composites and its practical application

A multi-stage technique for applying insulating coatings to metal powder particles has been developed in order to create a new class of Fe-based soft magnetic materials with improved characteristics. The density value calculated from the data of X-ray diffraction analysis is approximately 3 % higher than the experimentally measured values, which are 7.4–7.45 g/cm3. The low porosity of the composites is confirmed by the SEM and EDX results. The proposed method of encapsulation of iron powder with an oxide layer is a highly economical method for applying coatings of various chemical compositions to metal powders, and can be widely used in practice to obtain electrical materials. Comprehensive studies of the properties of the obtained samples of powder composite materials based on ABC100.30 iron, the particles of which are encapsulated with phosphorus oxide, have been carried out. It has been established that in a field of 1.5 T, the losses at a frequency of 1 kHz decrease 10 times with an increase in the thickness to 30 nm. The synthesized materials are recommended for use in the development of various types of high-frequency electric motors, generators, chokes, magnetic circuits and electrodes for high-frequency welding and other applications.

New biocompatible low modulus and high strength β Ti-Fe-Nb-Sn ultrafine eutectic composites

High strength β Ti–Fe–Nb–Sn ultrafine eutectic composites are promising in structural and functional applications exhibiting high fracture strength with large plasticity. The present work aims to develop new biocompatible β Ti–Fe-based ultrafine eutectic composites using biocompatible elements (Ti, Fe, Sn and Nb) and avoiding and/or controlling the formation of metastable ω phase also known as Laves phase. Five new compositions (Ti64Fe22Nb14, Ti66Nb18Fe16, Ti63Fe23Nb8Sn6, Ti60Fe23Nb8Sn9 and Ti44Fe34Nb16Sn6 (at.%) were produced using Cu-mold suction casting and the evolution of phases and microstructure with the cooling rate and their mechanical properties were investigated. In this sense, was observed a decreasing in the melting point by the addition of eutectoid β-stabilizing elements (Fe and Sn), which leads to values down to Tl = 1215 °C. The samples were characterized by X-ray diffraction, differential scanning calorimetry, scanning and transmission electron microscopy, Young's modulus measurements by the ultrasonic method, microhardness and compression tests. Thus, in this paper are shown promising results on new biocompatible metallic alloys of the TiFeNbSn system with high strength and low Young's modulus due to the adequate combination of a microstructure formed by micrometer-sized β-Ti dendrites with ultrafine eutectics between soft β-Ti phase and hard Ti–Fe and Ti3Sn intermetallics, highlighting alloys Ti64Fe22Nb14 and Ti63Fe23Nb8Sn6. Their yield and fracture strength measured by compression and Young's Modulus measured by ultrasound were 1810 MPa, 2160 MPa and 45 GPa for alloy Ti64Fe22Nb14 and 1915 MPa, 2240 MPa and 59 GPa for alloy Ti63Fe23Nb8Sn6 (at.%)

Consolidation and wear resistance of Fe based bulk metallic glass composites by spark plasma sintering

High densification and wear resistance are essential for the application of Fe-based bulk metallic glass composites. In this work, Fe-based composites were fabricated by spark plasma sintering. Firstly, under the pressure of 150 MPa, all samples achieved high densification, the microcontact pressure between powder particles decreased with increasing density. Then, as the sintering temperature was increased from 350 °C to 450 °C, the crystalline phases were identified as Fe3Si and Fe2B. The hard borides improved the hardness and wear resistance of composites. Finally, at sintering temperature of 400 °C, the sample exhibited the highest micro-Vickers hardness of 1168.8 Hv and the lowest friction coefficient of 0.59, the coefficient of friction was lower than that of bearing steel. FeSiB BMG composites showed dominant abrasive and oxidative wear mechanisms. FeSiB composites showed excellent hardness and wear resistance, which extends the potential application of bulk metallic glass in the field of engineering structural materials.

Microstructure and Internal Friction Behavior of Laser 3D Printed Fe-Based Amorphous Composites

Microstructure and Internal Friction Behavior of Laser 3D Printed Fe-Based Amorphous Composites

Effect of mechanical milling on powder characteristics of Fe-based metal matrix composites reinforced with WC–Co and NbC particles

Effect of mechanical milling on powder characteristics of Fe-based metal matrix composites reinforced with WC–Co and NbC particles

Wide induction range analysis of DC magnetic properties and magnetization processes of Fe-based soft magnetic composites

The paper presents systematic analyses of a wide maximum induction range (0.001 T–1.4 T) DC magnetic properties of iron-based soft magnetic composite (SMC) materials by applying different methods to understand the specific features of magnetization reversal of this increasingly popular class of soft magnetic materials, including a hitherto less explored area of the Rayleigh region of very low magnetic fields, which has growing application potential in new, low-energy consuming electronic devices or ultra-low magnetic field shielding. The total permeability, coercive field and remanent magnetic induction were analysed in connection with the reciprocity factor and inner demagnetization factor and their relations to interparticle magnetic interaction, domain wall movability and predominance of individual magnetization processes. Their dependence on the magnetic induction and the properties of each sample were revealed and confirmed also by energy loss separation. The Rayleigh region analytical expressions for the coercive field, remanent magnetic induction, the ratio of irreversible to reversible magnetization changes and their percentages within the magnetizing cycle were used for SMCs for the first time.

Unprecedented heat resistance of Fe-based soft magnetic composites realized with tunable double insulation layer: Synergy of MgO diffusion barrier and void-filling SiO2 layer

Soft magnetic composites (SMCs) comprising surface-insulated Fe powders have attracted significant attention owing to their capability of producing innovative three-dimensional cores with high magnetic flux density and their potential utilization in various electrical machinery fields. The aim of this study is to fabricate SMCs with an inorganic double insulating layer, which can substantially enhance heat resistance and enable enhanced magnetic and mechanical performance through high-temperature annealing. Herein, SMCs with different inorganic coating materials (single layers of SiO2, MgO, and PO4 and double-layers of MgO and SiO2) were prepared by a sol–gel method and powder compaction. In particular, a certain double-layered SMC core (Fe@MgO@SiO2) exhibited retention of internal insulation matrix even after annealing at 900 °C and a significantly suppressed core loss owing to synergistic effects of a diffusion barrier in the primary layer and an electrical insulator in the secondary layer. As anticipated, high-temperature heat treatment at > 700 °C reduced coercivity, which enhances permeability and hysteresis loss of SMCs. The double-layered SMCs also showed an increase in flexural strength of 280% when the annealing temperature was increased from 600 to 900 °C.

Recent Advances and Prospects of FeOOH-Based Electrode Materials for Supercapacitors

Supercapacitors (SCs) offer a potential replacement for traditional lithium-based batteries in energy-storage devices thanks to the increased power density and stable charge–discharge cycles, as well as negligible environmental impact. Given this, a vast array of materials has been explored for SCs devices. Among the materials, iron oxyhydroxide (FeOOH) has gained significant attention in SC devices, owing to its superior specific capacitance, stability, eco-friendliness, abundance, and affordability. However, FeOOH has certain limitations that impact its energy storage capabilities and thus implicate the need for optimizing its structural, crystal, electrical, and chemical properties. This review delves into the latest advancements in FeOOH-based materials for SCs, exploring factors that impact their electrochemical performance. To address the limitations of FeOOH’s materials, several strategies have been developed, which enhance the surface area and facilitate rapid electron transfer and ion diffusion. In this review, composite materials are also examined for their synergistic effects on supercapacitive performance. It investigates binary, ternary, and quaternary Fe-based hydroxides, as well as layered double hydroxides (LDHs). Promising results have been achieved with binder-free Fe-based binary LDH composites featuring unique architectures. Furthermore, the analysis of the asymmetric cell performance of FeOOH-based materials is discussed, demonstrating their potential exploitation for high energy-density SCs that could potentially provide an effective pathway in fabricating efficient, cost-effective, and practical energy storage systems for future exploitations in devices. This review provides up-to-date progress studies of novel FeOOH’s based electrodes for SCs applications.

Carbon-coated Fe3C derived from MIL-100 growth on covalent triazine framework in situ as an efficient ORR catalysts

Fe-based N-doped carbon materials have become the most potential electrocatalysts to replace noble metal catalysts in oxygen reduction reaction (ORR) due to their wide availability, affordability, and high catalytic activity. In this study, novel Fe-based Fe3C nanoparticles encapsulated by N-doped mesopores carbon were prepared via a cost-effective method using MIL-100(Fe) growth on CTF as the precursor. Benefit from the compositional and structural synergistic effect of metal and substrate, the highly dispersed core–shell Fe/Fe3C@C catalyst shows excellent ORR activity and stability with an onset potential of 1.016 V and a half-wave potential of 0.831 V, which is comparable with commercial Pt/C. Meanwhile, the interfacial electron transfer between Fe3C nanoparticles and neighboring Fe-N species, as well as the porous carbon architecture, contribute to the excellent ORR performance. The CTF-derived synthetic enhances ORR activity strategy inspires new perspectives to develop Fe-based composites as high-efficiency ORR electrocatalysts.

Microstructure evolution and soft magnetic properties of Fe-based nanocrystalline soft magnetic composites coated with lubricant

Here, the influence of zinc stearate on the microstructure and soft magnetic properties of the Finemet nanocrystalline soft magnetic composites (NSMCs) was systematically investigated. The results demonstrate that the core loss (Pcv) decreases and the effective permeability (μe) increases of the NSMCs with increasing zinc stearate from 0 wt% to 2.0 wt%, which can be attributed to the reduction of residual stress during compaction. Further increasing zinc stearate up to 3.0 wt%, the Pcv increases sharply, while the μe shows a decreasing trend. It can be considered that the addition of excess lubricant decomposes to CO2 during annealing, which deteriorates the magnetic properties. After annealing at 560 °C, a thin hybrid layer of only about 53.6 nm containing iron phosphate, ZnO, and SiO2 is formed in the NSMCs with 2.0 wt% zinc stearate, which exhibits excellent soft magnetic properties such as low Pcv of 174 kW/m3 and high μe of 66.7 at Bm = 0.1 T for 50 kHz. In addition, loss separation has been carried out and suggests that the addition of lubricant mainly affects hysteresis loss in the total energy loss of NSMCs.

Influence of SiC polytypes on the mixed lubrication regime of self-lubricating composites containing in situ generated 2D turbostratic graphite

Fe-based self-lubricating composites, in which SiC particles act as precursors to in situ generated 2D turbostratic graphite as a lubricating phase, were produced via powder injection moulding (PIM). In order to study the precursor influence on the solid lubricant structure and properties, hexagonal (α) and cubic (β) SiC polytypes were used. The composites were tribologically tested in dry and low-viscosity oil-lubricated conditions. Distinct precursors did not lead to significant differences between composites. However, due to the highly disordered graphite-rich tribolayer formation, they do provide lubricity, low friction coefficient, and high wear resistance, even in oil-lubricated conditions.