Fluidized Bed Chemical Vapor Deposition Research Articles

Design, preparation and diffusion research of the W coating used in W-based cermet for nuclear thermal propulsion

The fissile fuel agglomeration and loss in the tungsten (W) based ceramic-metallic (cermet) fuel element are the major challenges for application in nuclear thermal propulsion (NTP). The previous research indicated that a W coating deposited on the surface of uranium dioxide (UO2) by the fluidized bed chemical vapor deposition (CVD) technique is an efficient way to achieve the uniform distribution of fuel particles and reduce fuel loss simultaneously. However, the W layers' resulting thicknesses differ, which is not conducive to achieving high fuel loading. Therefore, in this study, the appropriate thickness of the W coating is first investigated by COMSOL Multiphysics modeling. Through contrastive analyses, the W layer with a thickness of about 5–10 μm is considered to be the optimal choice, where the maximum loading capacity of the fissile fuel can be achieved with a volume fraction of about 60%. Based on the above calculations, the CVD technique is employed to produce the optimized thickness of the W layer by precisely adjusting the deposition time at 900 °C. This approach is taken after determining the critical influencing factor that governs the performance of the W layer. Experimental results show that the highly dense W layer presents a uniform thickness and fine-grained size. As the only structural and protective layer, the application of this W coating provides a barrier for blocking the inward diffusion of hydrogen (H2) to stop the detrimental chemical reactions between UO2 and H2, thus lowering fuel loss. The spark plasma sintering (SPS) demonstrates that zirconium dioxide (ZrO2) particles as the surrogate for UO2 exhibit a homogeneous distribution without any direct contact in the W matrix because of the presence of the W coating. Despite the fact that the interface between the W coating and the W matrix exhibits remarkable bonding, making it difficult to clearly discern the boundaries due to surface diffusion and atomic binding, the existence and integrity of the W coating after high-temperature sintering is unequivocally confirmed through interface TEM observations and the uniform dispersion of coated particles within the W-Y2O3 matrix. Furthermore, the fine-grained W coating has been demonstrated to effectively hinder the diffusion of H2 isotopes through permeation and diffusion tests. This comprehensive study not only aids in establishing the optimal geometrical thickness for the W coating but also underscores its pivotal role in W-based cermet fuels for NTP system.

Ar-ion- and electron-irradiated ZrC layers in ZrC-SiC-coated surrogate TRISO fuel particles

Surrogate tristructural isotropic (TRISO) particles, including ZrC and SiC layers, were manufactured through fluidized-bed chemical vapor deposition and irradiated. ZrC layers exhibited C/Zr atomic ratio of 0.95 without distinct crevices at interfaces in microscopy, but underwent significant microstructural changes post-irradiation. Defects included black dots and Frank loops, with increasing irradiation doses augmenting their area fractions. Frank loop density reduced at 9.4dpa due to the formation of fewer, fully circular loops. The ZrC hardness and modulus rose by 25% and 26% following Ar-ion irradiation at 9.4dpa, linked to the formed defects and implanted Ar ions. Electron irradiation expanded the defect-prone zone up to 100nm from the ZrC grain boundary and led to ZrO2 formation. ZrC grains recrystallized post electron irradiation at 700 °C, causing initial grain decomposition, amorphization, and nanocrystal formation. These nanocrystals, formed at 3.3dpa, closely aligned with ZrC diffraction patterns with no preferred orientations.

S-doped mesoporous graphene modified separator for high performance lithium-sulfur batteries

Due to their low cost, environmental friendliness and high energy density, the lithium-sulfur batteries (LSB) have been regarded as a promising alternative for the next generation of rechargeable battery systems. However, the practical application of LSB is seriously hampered by its short cycle life and high self-charge owing to the apparent shuttle effect of soluble lithium polysulfides. Using MgSO4@MgO composite as both template and dopant, template-guided S-doped mesoporous graphene (SMG) is prepared via the fluidized-bed chemical vapor deposition method. As the polypropylene (PP) modifier, SMG with high specific surface area, abundant mesoporous structures and moderate S doping content offers a wealth of physical and chemical adsorptive sites and reduced interfacial contact resistance, thereby restraining the serious shuttle effects of lithium polysulfides. Consequently, the LSB configured with mesoporous graphene (MG) as S host material and SMG as a separator modifier exhibits an enhanced electrochemical performance with a high average capacity of 955.64 mA h g−1 at 1C and a small capacity decay rate of 0.109% per cycle. Additionally, the density functional theory (DFT) calculation models have been rationally constructed and demonstrated that the doped S atoms in SMG possess higher binding energy to lithium polysulfides than that in MG, indicating that the SMG/PP separator can effectively capture soluble lithium polysulfides via chemical binding forces. This work would provide valuable insight into developing a versatile carbon-based separator modifier for LSB.

Characterization of fluidized bed chemical vapor deposition ZrC coatings on PyC/YSZ kernels deposited under differing conditions

Coated fuel particle architectures with ZrC coatings are candidate fuels for advanced power reactors and space nuclear propulsion (SNP) concepts. Owing to its relevance to SNP, the composition, microstructure, and mechanical properties of eight ZrC coatings prepared by fluidized bed chemical vapor deposition were evaluated. Evaluation by SEM and EBSD showed that all grains were columnar. Across the various examined samples, minor axis diameters varied between 0.3 and 1.1 μm, and major axis diameters varied between 0.4 and 2.3 μm. Major and minor diameters increased with thickness particularly at higher deposition temperatures in which the major grain axis (from an ellipse fit to the grain shape) increased by 2.5 μm over the entire coating. Coatings with higher reactive gas flows and Zr/C concentrations closer to 1 were observed to contain nanocrystalline graphite deposits. Reactive gas flow doubling led to increases in coating thickness from around 10–15 μm to around 22–27 μm.

Fluidized Bed Chemical Vapor Deposition on Hard Carbon Powders to Produce Composite Energy Materials.

Herein, we report a general route for the uniform coating of hard carbon (HC) powders via fluidized bed chemical vapor deposition. Carbon-based fine powders are excellent substrate materials for many catalytic and electrochemical applications but intrinsically difficult to fluidize and prone to elutriation. The reactor was designed to achieve as much retention of powders as possible, supported by a computational fluid dynamics study to assess the hydrodynamic behavior for varying gaseous flow rates. Solutions of the tin seleno- and thio-ether complexes [SnCl4{nBuSe(CH2)3SenBu}] and [SnCl4{nBuS(CH2)3SnBu}] were used as single source precursors and injected at high temperature into a fluidized bed of HC powders under nitrogen flow. The method allowed for the synthesis of HC-SnSx-SnSe2 composites at the gram scale with potential applications in electrocatalysis and sodium-ion battery anodes.

A new design of composite fuel with Zr-coated TRISO particles dispersed in metal matrix

With the development of advanced reactors, it is critical to improve the safety of nuclear reactors. Safety primarily depends on the ability to block fission products and the ability to discharge decay heat of fuel elements. To enhance the ability to retain the release of fission products and achieve high thermal conductivity, a novel fuel pellet was developed, consisting of zirconium (Zr)-coated TRISO particles embedded in a zirconium metal matrix. The zirconium coating was deposited via fluidized-bed chemical vapor deposition (FB-CVD), and the deposition mechanism of Zr coating via FB-CVD was proposed. The consolidation process of Zr-coated TRISO particles in the Zr matrix was achieved via spark plasma sintering (SPS). The microstructure and mechanical properties of Zr coating and the pellet were investigated via SEM and nanoindenter. The results proved the effectiveness of zirconium coating in preventing TRISO fuel particles from contact and cracking during sintering.

A new route to apply nanometric alumina coating on powders by fluidized bed chemical vapor deposition

A new route to deposit alumina nanometric thin films on powders from the single source Aluminum Tri-Isopropoxide (ATI) precursor is developed using the Fluidized Bed Chemical Vapor Deposition (FBCVD) process. For this study, an easy-to-fluidize silica powder is used, as a first step to ultimately coat cohesive oxygen sensitive powders. The FBCVD process has been studied under mild temperature conditions (400–500 °C), without any containing oxygen co-reactant. The influence of the deposition parameters (temperature, total flow rate, precursor inlet molar fraction) on the process behavior (ATI vaporization rate, fluidized bed thermal profile, deposition yield) and on the coating characteristics (composition, thickness, morphology) is analysed in details. Results show that for all conditions tested, the fluidization is maintained and the bed remains almost isothermal all along the deposition experiments, allowing for a uniform coating of the whole particles of the bed. Continuous and conformal nanometric films are obtained, mainly formed of non-carbon contaminated alumina, containing however a small amount of hydroxyl bonds that could be due to air contamination. The proof of concept of using FBCVD from ATI to produce nanometric stoichiometric alumina coatings on powders is then demonstrated, opening the way for new applications.

Carbon coating optimization on porous silicon as high-performance anode material via fluidized bed chemical vapor deposition

The carbon layer coating is a promising solution to volume expansion and low electron conductivity in silicon-based anodes during lithiation. While numerous methods exist to generate these carbon coatings, Fluidized Bed Chemical Vapor Deposition (FBCVD) has proven superior due to its capacity for producing remarkably uniform and consistent carbon layers, primarily as a result of efficient mass and heat transfer characteristics. However, its application in the context of lithium-ion battery anodes has been sparsely explored and has been principally limited to silicon oxide as the base material. In this paper, porous silicon (PSi) obtained through acid etching of AlSi alloy with an average particle size of 300 mesh was taken as raw materials, and a fluidized bed reactor was employed to realize a uniform and tightly packed carbon layer. Relatively speaking, the PSi@C30 in this work offers a simpler process and promising electrochemical performance, opening a new door for the preparation of high-performance silicon-carbon anodes by FBCVD. Besides, PSi and high-quality carbon layers with structural advantages enabled the authors to obtain high-performance silicon-carbon anode materials. The resulting PSi@C30 composite demonstrated excellent initial coulomb efficiency (88.8 %) and cycling stability (with 83 % capacity retention after 100 cycles at 0.5 A g-1 and a reversible capacity of 1408 mAh g-1). Such a cost-effective and user-friendly technique facilitates the application of FBCVD in silicon-based anode materials for Li-ion batteries, thus accelerating the industrialization of silicon-carbon anodes for high-performance Li-ion batteries in the future.

Fluidized bed chemical vapor deposition of pyrocarbon on various types of powders: Heat and mass transfer analyses and nanotexture characterization

SiC powders coated by pyrocarbon are a promising feedstock for the synthesis of Ceramic-matrix composites. Preparing such powders is possible using low pressure Fluidized-Bed Chemical Vapor Deposition (FB-CVD) with propane as a precursor at 1000 °C. A preliminary study on non-porous and porous alumina powders as substrates has been carried out. With the help of a numerical assessment of heat transfer in the reactor, it has been possible to optimize the setup and achieve excellent deposition yields (up to 100%), even inside very small pores (7 nm), and transpose the protocol to 200-nm diameter SiC powders. The microstructure and texture of the deposits were characterized by TEM, showing dependence to pore size due to a texture-induction effect by the substrate surface. A quantitative assessment of mass transfer indicated that the results obtained here agree with past studies on FB-CVD of other materials and on pyrocarbon CVD on flat substrates.

Realizing high-resistivity and low-loss Fe–Si–Al based soft magnetic powder cores through interfacial chemistry regulation

As a symbolic ceramic oxide, SiO2 is one of the most important insulating layers of soft magnetic powder cores (SMPCs). Thus, the reaction of SiO2 with Fe–Si–Al based SMPC substrates during annealing, the induced phase transition of the core-shell structure, and the influence of the latter on the magnetic characteristics of SMPCs are worth investigating. In this study, Fe–Si–Al based SMPCs were successfully synthesised using fluidised-bed chemical vapour deposition (FB-CVD) at various times, combined with an electric pressure-assisted sintering method and high-temperature annealing. The evolution of the insulating layers with different thicknesses was investigated. With increasing thickness, the insulating layers (shell) gradually transformed into Al2O3 and the Fe–Si–Al substrate (core) to Fe3Si. The newly formed Al2O3 and Fe3Si increased the coercivity and saturation magnetisation of the SMPCs, while the hysteresis loss increased with thicker insulating layers. The generated Al2O3 improved the integrity of the insulating layers, preventing possible point contact between particles, and significantly reduced the Eddy current losses. The SMPCs with the thickest insulating layers (7#) exhibited superior magnetic properties (Ms = 129.3 emu/g, resistivity = 2.51 mΩ cm, total loss = 593.1 kW/m3 at 10 mT and 100 kHz; 18.0% reduction from the maximum). Thus, a precise method of adjusting the magnetic behaviour of Fe–Si–Al based SMPCs was developed through the novel approach of building SMPCs with inorganic ceramic insulating layers, enabling a comprehensive understanding of the relationship between the thickness of insulating layers and magnetic properties, which is of significance for industrial production.

In-situ fabrication of Si/FeSi2@C NPs with volume control effect by fluidized bed chemical vapor deposition as anode materials

Silicon (Si) has been proven to be the most potential anode material for the next-generation lithium-ion batteries (LIBs) because of its superior theoretical capacity (∼4200 mAh g−1). However, the huge volume changes, unstable solid-state interphase (SEI) layers, and large internal stresses upon the lithiation process severely limit the practical application for commercial LIBs anodes. Herein, we fabricate the carbon-coated Si/FeSi2 nanoparticles (Si/FeSi2 @C NPs) with volume control effect by fluidized bed chemical vapor deposition (FBCVD) method to solve the above-mentioned problems. These 15 min-Si/FeSi2 @C NPs and 30 min-Si/FeSi2 @C NPs show excellent Li+ storage capacity in the first cycle (2705.9/3039.1 mAh g-1 and 2645.9/2984.2 mAh g-1) with high Initial Coulombic Efficiency (ICE) of ∼89.0% and 88.7%. In-situ TEM characterization demonstrates that the carbon coating layer and inert FeSi2 phase enable a small volume variation, only ∼37.8%, revealing the effective volume expansion control effect, and generating thin SEI layers. Besides, the perfect structure of Si/FeSi2 @C NPs makes this material a great improvement in rate performance.

Preparation of ZrC coating in TRISO fuel particles by precise transportation of solid precursor and its microstructure evolution

Very-high-temperature gas-cooled reactors (VHTRs) with outlet temperatures above 1273 K show higher thermal efficiencies, which require fuel elements to operate at higher temperatures. In such situations, the conventional silicon carbide (SiC) coatings in TRISO particles might not be able to adapt to such high temperatures, and zirconium carbide (ZrC) can function as a potential fission product barrier material. For ZrC coating, controlling the stoichiometric ratio is a key challenge in the preparation process in fluidized bed. In this paper, a novel solid precursor feeding mode was proposed, combining quantitative powder feeding with cold transport. By controlling the powder feeding rate of ZrCl4 and the flow rate of propylene, the C/Zr atomic ratio in ZrC coating was controlled accurately. ZrC coatings with different stoichiometric ratios were successfully prepared via fluidized-bed chemical vapor deposition (FB-CVD). The ZrC coatings were subjected to high temperature heat treatment for different times from 2473 to 2673 K under argon atmosphere and the microstructure and property evolutions after high-temperature heat treatment were investigated. The deposition mechanism of ZrC coating was proposed.

CFD-DEM study on mixing characteristics of ZrO2 particles using the fluidized bed-chemical vapor deposition method

Fluidized bed-chemical vapor deposition (FB-CVD) is the key method to prepare low-temperature isotropic pyrolytic carbon (LTIC) for artificial heart valve. In the process of FB-CVD of pyrolytic carbon, ZrO 2 hollow particles are not only the bed particles forming the fluidized bed, but also play the role of heat carrier in the pyrolysis reaction of carbon source gas. The mixing degree of particles directly affects the coating quality of pyrolytic carbon. In this paper, a coarse-grained CFD-DEM model is used to conduct 3D numerical simulation of fluidized bed to investigate the effect of fluidization wind speed on the mixing characteristics (particle distribution, particle motion and Lacey index) of ZrO 2 hollow particles from the particle perspective. The results show that the mixing process can be accelerated by increasing the fluidization wind speed within a reasonable range, and radial mixing is more sensitive to fluidization wind speed than axial mixing. In addition, due to the different densities of particles in the furnace along the radial direction, the number of particle collisions and the influence of traction also differ greatly, resulting in more significant changes of particle velocity in the fountain area, while the velocity distribution in the annular gap area near the wall is relatively smooth.

Elimination of ƞ phase in WC–Co cemented carbides during laser powder bed fusion by powder coating compensation strategy

AbstractThe formation of ƞ phase induced by the C‐loss for the laser powder bed fusion (LPBF) of WC–Co cemented carbides largely deteriorates the fracture toughness. The current approach of mixing C additive into powder cannot mitigate the ƞ phase formation. This study proposed a new carbon compensation strategy of coating carbon resource on powder surface by fluidized bed chemical vapor deposition to address this issue. C nanoparticles and carbon nanotubes (CNTs) were selectively deposited on WC–Co powder to make uniform C‐ and CNTs‐coated powders by tuning the deposition temperature. Compared with CNTs‐coated powder and C–WC–Co powder mixtures, the C‐coated powder was more effective in impeding the ƞ phase formation because it had higher reactivity and stronger dissolution ability to compensate the C‐loss in the Co–W–C liquid. However, the single‐carbon compensation was not enough to eliminate the ƞ phase due to the extreme nonequilibrium characteristics of LPBF, which required secondary heat treatment. The conventional heat treatment procedure of 1000°C for 3 h eliminated the ƞ phase for the C‐coated powder but failed for the C–WC–12Co powder mixtures. Because of the absence of ƞ phase, the heat‐treated sample made from C‐coated powder exhibited the highest transverse rupture strength.

Effects of process parameters on preparation of Ti@SiO2 particles during fluidized bed chemical vapor deposition via design of experiments

Fluidized bed chemical vapor deposition (FBCVD) is a promising technology for preparing photocatalysts. However, the photocatalyst performance depends on numerous parameters, and the effects of process parameters on photocatalyst performance are not well understood. In this work, the effects of deposition time, fluidization number, reactant molar ratio and deposition temperature on photocatalysts prepared by FBCVD are investigated via a full factor factorial design approach, which is a kind of Design of Experiments. The results show that the deposition time, reactant molar ratio and deposition temperature are the main factors affecting the photocatalytic performance, while the fluidization number and the interactions between different parameters are insignificant factors. The characterization of the elemental content, elemental distribution and crystalline structure of Ti-deposited SiO2, Ti@SiO2, particles reveals that the formation of Ti-O-Si bonds and Ti-based nanoparticles on the Ti@SiO2 surface enhances the photocatalytic performance of the particles. Finally, the formation mechanisms of Ti@SiO2 particles are summarized which can be distinguished into two stages. At around 120 °C, intermediates such as Ti(OH)4 are generated and reactions consist of homogeneous and heterogeneous reactions. At around 400–600 ℃, the Ti@SiO2 particles are formed, which is dominated by heterogeneous reactions. The results of this study can improve understanding and control of photocatalyst preparation.

(Invited) Production and Functionalization of Carbon Nanotubes for Electrochemical Energy Storage Devices

Self-supporting, sponge-like paper of carbon nanotubes (CNTs) can be a new platform for high energy/power density batteries. Presently, battery electrodes are built on metallic foils having only two faces and large mass with the aid of polymeric binders and conductive fillers. CNT paper can replace all these components. Furthermore, it captures nanomaterials at high loading, activates insulative materials, and moderates volumetric change of active materials.We have developed semi-continuous fluidized bed chemical vapor deposition method [1], which yields submillimeter-long few-wall CNTs with carbon purity >99 wt% and metal impurity <0.1 wt% [2]. By capturing capacitive particles (99 wt%) with CNTs (1 wt%), a lithium ion full cell with graphite-CNT anode and LiCoO2-CNT cathode is demonstrated (Figure 1b) [3]. This platform is also effective to create electrodes of the emerging active materials such as Si anode [4] and S cathode [5] with practically high gravimetric, areal, and volumetric loadings, and realized Li x Si-S and Li-Li2S x full cells [6,7]. In addition, by combining with the insulative sponge of boron nitride nanotubes (BNNTs), the graphite-CNT|BNNT| LiCoO2-CNT full cell with high thermal stability was developed [8].[1] D.Y. Kim, et al., Carbon 49, 1972 (2011).[2] Z. Chen, et al., Carbon 80, 339 (2014).[3] K. Hasegawa and S. Noda, J. Power Sources 321, 155 (2016).[4] T. Kowase, et al., J. Power Sources 363, 450 (2017).[5] K. Hori, et al., J. Phys. Chem. C 123, 3951 (2019).[6] K. Hori, et al., Carbon 161, 612-621 (2020).[7] Y. Yoshie, et al., Carbon 182, 32-41 (2021).[8] K. Kaneko, et al., Carbon 167, 596-600 (2020).Figure 1. (a) Semi-continuous production of submillimeter-long few-wall CNTs by fluidized bed [1]. (b) Lithium ion full cell made of graphite-CNT anode and LiCoO2-CNT cathode [3]. Figure 1

Laser powder bed fusion of cemented carbides by developing a new type of Co coated WC composite powder

The study addresses the issue of the absence of high-quality WC-Co composite powder for laser powder bed fusion and assessing the printability of the new powder in terms of densification, microstructure and mechanical properties. The fluidized bed chemical vapor deposition (FBCVD) combined with electroless plating process was adopted to make core-shell structured WC-Co composite powder. The excellent uniformity of Co and good powder flowability were achieved by tuning the size and distribution of Co catalyst during FBCVD and regulating their relationship to the subsequent electroless plating behavior. The newly developed composite powder exhibited excellent printability. The densification mechanism was largely dependent on the laser energy density. The liquid formed by the melting of Co was responsible for the densification at low laser energy density, while the Co-W-C ternary liquid resulted from the dissolution of WC into Co melt dominated the densification at high laser energy density. Microstructurally, the morphology and size of WC grains were insignificantly changed because of its non-participation with liquid formation at low laser energy density. The rectangular/triangular WC grain morphology similar to the traditional sintered was formed at high laser energy density because of the precipitation of WC from the Co-W-C ternary liquid. Affected by the different liquid formation processes, increasing laser energy density increased the relative density, promoted the W 2 C phase formation and decreased WC grain size, which remarkably improved the hardness and tribological properties of the printed cemented carbide.

Experimental study on the scale-up of a multi-ring inclined nozzle spout-fluid bed by electrical capacitance tomography

Abstract Scale-up studies of fluidized beds are important for numerous fields. Fluidization in a multi-ring inclined nozzle spout-fluid bed (MRIN spout-fluid bed) is one of the most critical factors that affect the coating efficiency and uniformity of tri-structural isotropic (TRISO) nuclear particles in the fluidized bed chemical vapor deposition (FB-CVD) process. In this work, the flow pattern similarity principle was proposed to scale up a specially designed spout-fluid bed, which was aimed at maintaining the gas-solid contact efficiency, and was validated by electrical capacitance tomography (ECT) measurements. First, the traditional ECT method was developed for the specially designed MRIN spout-fluid bed according to the filling method. Then, the reconstruction algorithms were updated using the alternating direction multiplier method (ADMM) by introducing optimization constraints. The fluidization laws were investigated for different superficial gas velocities and distributor structures. We found that the gas distributor structure affected the merge point of the jets, which played an essential role in fluidization pattern changes. The statistically-based coefficient of variation (Cv) was proposed to distinguish the different flow patterns. Multi-ring spouting was then selected as a typical flow pattern for good fluidization and mixing, where the Cv ranged from 0.25 to 0.65. Then, the optimal design principles for the enlarged spout-fluid bed gas distributor were obtained. We determined that a smaller nozzle diameter (0.71d 0), larger nozzle spacing (1.12x 0), and slightly inclined angle (1.50θ 0) could improve fluidization, and that nozzle spacing was the most important factor. This study may be beneficial for the industrial design of the FB-CVD process and for the fabrication of high-density nuclear fuel particles. Additionally, it could be presented to a more general audience for scaling-up fluidized beds with a complex distributor, which would be beneficial for the fluidization research community.

Development of a novel silica-based microwave receptor for high temperature processes

A novel silica-based microwave receptor was developed via a fluidized bed chemical vapor deposition (FBCVD) technique. In this study, the silica sand particles were successfully coated in an induction heating-assisted reactor, with carbon produced from thermal degradation of methane (TDM) at various reaction temperatures and times. The effect of FBCVD reaction parameters, temperature and reaction time, on the amount of carbon deposition, and the composition, coherence and thickness of the carbon coating layer were investigated using thermogravimetric and morphological analysis, respectively. The microwave heating performance of such developed receptors was further investigated in an innovative single-mode microwave apparatus and was subsequently compared with the relevant performance of sand and graphite particle mixtures. The developed microwave receptor stipulates low level of carbon content and high layer uniformity, extreme microwave heating rate, high durability, and excellent potential for application in gas-solid fluidized bed reactors as heat generator and catalyst support/promoter simultaneously.

Development of quantitative parameter–property relationship and technology parameter choosing software of Fe(Si)–SiO2 soft ferromagnetic composites

Intelligent technology parameter choosing software is the future development trend of realizing precisely control and efficient production. However, the technology parameter choosing software has not been reported probably due to the lack of in-depth understanding of quantitative relationship between technology parameter and magnetic properties for soft ferromagnetic composites. This paper describes a novel strategy to construct quantitative relationship model and develop technology parameter choosing software. Using gas precursor concentration parameter during fluidized bed chemical vapor deposition as an example, the microstructure and performances of Fe(Si)–SiO2 soft ferromagnetic composites obtained were systematically studied. The quantitative relationships between gas precursor concentration and magnetic performances were built based on the gas precursor concentration dependence of SiO2 insulating layer thickness and other classical theoretical models. The findings suggest that the saturation magnetization increase with the gas precursor concentration; however, the impacts of the gas precursor concentration on electrical resistivity and eddy current loss are relatively complex. Informed by these quantitative relationship models, the supporting software has been designed, which can configure the technology parameter automaticity according to the target performance of soft ferromagnetic composites. The results may deepen the understanding on the quantitative relationship and provide ideas for developing efficient production control software.