Synthesis Of Silicon Carbide Research Articles

Polymer‐Derived High‐Temperature Nonoxide Materials: A Review

This review is focused on an attractive class of polymer‐derived high‐temperature ceramics, namely, polymer‐derived nonoxide materials. With a brief introduction of high‐temperature nonoxides, the origin of using polycarbosilane (PCS) polymer melt spinning to synthesize silicon carbide (SiC) fibers is traced back. For SiC formation, the four stages for the conversion from polymer precursors to microcrystalline ceramics are examined first: crosslinking, polymer decomposition, ceramic formation, and crystallization. Also, the important parameters related to PCS pyrolysis are explained, and polymer‐derived SiC microstructures and compositions are evaluated. Solid‐solution carbides and transition metal carbides are further reviewed. For boride materials, the discussion is focused on transition metal borides and boride composites. Similar to PCS conversion to SiC, nitride materials mostly start with polycarbosilazane (PSZ) precursors and form into the final materials through pyrolysis. With different carbide and nitride precursors mixed and pyrolyzed together, high‐temperature nonoxide composites are formed. Such molecular‐level intermixing and versatile capability of forming different shapes enable many exciting properties. Among these are mechanical and thermal properties, along with electrical conductivity, electromagnetic shielding, and charge storage capability. An overview of applications of polymer‐derived nonoxides is provided, followed by a summary and outlook.

Application of Methane and Micro Silica for Silicon Carbide Synthesis

Application of Methane and Micro Silica for Silicon Carbide Synthesis

Microwave heating and mechanism for seed-induced synthesis of SiC

We prepared silicon carbide (SiC) through microwave heating using α-SiC particles, coal mineral particles, and tetraethoxysilane as seeds, carbon source, and silicon source, respectively. By characterising the phase and microstructure, the effects of different temperatures, holding time, and seed content on the growth of SiC crystals were studied. β-SiC and α-SiC particles were synthesised through microwave heating at 1100 °C for 10 min. An increasing holding time resulted in higher whisker yield. The crystal generation mode was through a vapor-vapor reaction, in which SiC crystallites formed on the surface of the α-SiC seeds via in situ nucleation and grain growth. The impedance matching between coal minerals and α-SiC seeds varied with the seed content, which also influenced the power redistribution, results in different heating rates, phases, and morphologies during microwave heating. The 15 wt% seed content was identified as the optimal value for both microwave heating effects and power redistribution, which promoted the formation of β-SiC whiskers. These results show that the rapid synthesis of SiC is achieved while coal as carbon source, which will greatly reduce cost to promote the commercialization of SiC via microwave heating.

Relating detonation parameters to the detonation synthesis of silicon carbide

Detonation synthesis of silicon carbide (SiC) nanoparticles from carbon liberated by negatively oxygen balanced explosives was evaluated in a 23 factorial design to determine the effects of three categorical experimental factors: (1) cyclotrimethylene-trinitramine (RDX)/2,4,6-trinitrotoluene (TNT) ratio, (2) silicon (Si) additive concentration, and (3) Si particle size. These factors were evaluated at low and high levels as they relate to the detonation performance of the explosive and the solid Si-containing phases produced. Detonation velocity and Chapman–Jouguet (C–J) detonation pressure, which were measured using rate stick plate dent tests, were evaluated. Solid detonation product mass, silicon carbide product concentration, and residual silicon concentration were evaluated using the x-ray diffraction analysis. The factors of Si concentration and the RDX:TNT ratio were shown to affect detonation performance in terms of detonation velocity and C–J pressure by up to 10% and 22%, respectively. Increased concentration of Si in the reactants improved the average SiC concentration in the detonation products from 1.9 to 2.8 wt. %. Similarly, increasing the ratio of RDX to TNT further oxidized detonation products and reduced the average residual Si remaining after detonation from 8.6 to 2.8 wt. %. A 70:30 mass ratio mixture of RDX to TNT loaded with 10 wt. % < 44 μm silicon powder produced an estimated 1.33 g of nanocrystalline cubic silicon carbide from a 150-g test charge. Using a lower concentration of added silicon with a finer particle size reduced SiC yield in the residue to 0.38 g yet improved the SiC to residual Si ratio to 1.64:1.

Electric Arc Synthesis of Silicon Nanostructures

The paper proposes a method for the synthesis of silicon carbide of microscopic sizes and silicon Nano formations in the form of nanotubes and nanofilaments in an argon arc. Graphite electrodes with silicon inclusions were used as arc discharge electrodes. The electrodes were placed in a plasma reactor in an upright position at an argon pressure of 485 Torr. During the discharge, carbon and silicon atoms evaporated from the anode surface. As a result of the experiment, deposits of silicon carbide were formed on the surface of the graphite cathode, and carbon-silicon nanostructures were formed on the surface of the anode. The synthesized samples were analyzed on an electron microscope.

Glass waste derived silicon carbide synthesis via direct current atmospheric arc plasma

The paper presents the results of the experimental studies addressing the production of silicon carbide from glass waste by electric arc plasma processing. A feature of the method is the possibility of its implementation without the use of vacuum equipment. It is possible due to the effect of self-shielding of the reaction volume from atmospheric oxygen. This approach significantly simplifies the design of the electric arc reactor and its performance. After plasma processing of various types of glass waste (such as bottle glass, window glass, medical glass, quartz glass, parts of worn-out scientific and industrial equipment), silicon carbide based material was produced. Silicon carbide was obtained from a mixture of various glass waste at a current 200 A, where blend was first purified from unbound carbon and then was consolidated by spark plasma sintering at 1800 °C and 60 MPa pressure for 10 min. As a result, a ceramic bulk sample was fabricated from a mixture of glass waste of various origin. Such sample was characterized with hardness of 14.8 GPa, and attained density of 92.5 %. Despite a possible increase in the density due to impurities and inhomogeneities, the hardness of the fabricated sample is comparable to that of other silicon carbide based materials, including commercial ones. Since the hardness of the produced silicon carbide based material is comparable to that of commercial materials, the use of glass waste of various origin could be feasible for synthesis of silicon carbide based powders.

Detonation synthesis of nanoscale silicon carbide from elemental silicon

Direct reaction of precursors with the products of detonation remains an underexplored area in the ever-growing body of detonation synthesis literature. This study demonstrated the synthesis of silicon carbide during detonation by reaction of elemental silicon with carbon products formed from detonation of RDX/TNT mixtures. Continuum scale simulation of the detonation showed that energy transfer by the detonation wave was completed within 2–9 μs depending on location of measurement within the detonating explosive charge. The simulated environment in the detonation product flow beyond the Chapman-Jouguet condition where pressure approaches 27 GPa and temperatures reach 3300 K was thermodynamically suitable for cubic silicon carbide formation. Carbon and added elemental silicon in the detonation products remained chemically reactive up to 500 ns after the detonation wave passage, which indicated that the carbon-containing products of detonation could participate in silicon carbide synthesis provided sufficient carbon-silicon interaction. Controlled detonation of an RDX/TNT charge loaded with 3.2 wt% elemental silicon conducted in argon environment lead to formation of ∼3.1 wt% β-SiC in the condensed detonation products. Other condensed detonation products included primarily amorphous silica and carbon in addition to residual silicon. These results show that the energized detonation products of conventional high explosives can be used as precursors in detonation synthesis of ceramic nanomaterials.

Features of silicon carbide synthesis by cold implantation of carbon recoil atoms

The Auger electron spectroscopy method confirmed a high concentration of carbon atoms (~ 85 at.%) introduced into silicon by cold implantation of recoil atoms. Carbon atoms are concentrated in a thin (~ 5 nm) near-surface region of silicon. Annealing of such a structure did not reveal a noticeable diffusion of carbon, which prevents obtaining a layer of SiC with a thickness of more than a few nm. This problem was solved by using radiation-enhanced diffusion. This made it possible to control the distribution profiles of carbon atoms in a wide range. Annealing at 1150oC allowed obtaining layers of amorphous-crystalline SiC with a thickness of 50-150 nm. Higher annealing temperatures are required to obtain a single-crystal SiC film. Keywords: cold implantation, radiation-enhanced diffusion, silicon carbide, recoil atom, thin films.

Formation of composite SiC-C coatings on graphite via annealing Si-melt in CO

A method for the synthesis of silicon carbide–graphite composite coatings is proposed and described. The method is based on the two simultaneous chemical reactions involving graphite. One of these reactions consists of the chemical interaction of a silicon molten mass with carbon monoxide on the surface of the graphite at a temperature slightly exceeding the melting point of silicon. It transforms Si into gaseous silicon monoxide (SiO) and SiC. Simultaneously, a second reaction involves the SiO in the transformation of the graphite itself into SiC. A coating with a thickness exceeding 1 mm is formed during the synthesis. The resulting coating has high mechanical strength and hardness. Samples of the composite coating were investigated via scanning electron microscopy, energy-dispersive spectroscopy , Raman spectroscopy , XRD, and nanoindentation . The coating has a complicated structure. It consists of a dense overlayer of SiC and has a branched structure consisting of dendrite-like SiC crystals extending into the depth of the graphite. The dendrites are interspersed with large (up to 20 μm) single-crystalline SiC grains consisting of predominantly cubic polytypes. The coating leads to significant hardening of the material: the composite has a hardness of 28 GPa, which is ~254 times higher than the hardness of the original graphite surface. • A method is proposed for the formation of protective SiC coatings on graphite. • The method consists of annealing of graphite with Si melt in presence of CO. • Thick, up to 1 mm coatings are being formed in 20 min at low T (1450C).

Study on mechanical properties and X-band microwave absorption properties of ER/SiCp/SiCf ternary composites

Despite the great advantages of the rapid developments in communication technology, it induces several serious intractable problem related to the electromagnetic interference with the environment and human civilization itself. To curb such issues, there is an urgent surge for the research on developing innovative microwave absorbing materials with improved corrosion and oxidation resistance, mechanical properties and microwave absorbing capabilities. In this context, this work is devoted to the facile synthesis of silicon carbide absorbing agents in powder (SiCp) and fiber (SiCf) structure using high-temperature carbothermic reduction process followed by catalyst induction method. Then the two materials were added into epoxy resin (ER, type E51) with different mass concentrations resulting in ER/SiCp/SiCf ternary composites as consequence of hot press molding process. The mechanical properties and microwave absorption performance in the X-band were studied. It is found that the introduction of SiCp/SiCf with excellent mechanical strength can significantly increase the tensile strength and bending strength of the ER subtract, which has a good toughening effect. The reasonable relative ratio of SiCp to SiCf brings favorable absorptipon performance to the composite material having a minimum reflection loss of the optimal sample in the X-band (RLmin = −63.91 dB), and the effective bandwidth is fE = 1.6 GHz. It is proved that integrating silicon carbide wave absorbing agent with high-performance resin is an effective strategy for designing microwave absorbing composite materials with improved performance.

Physicochemical Interaction Processes in the Carbon (Diamond)\u2013Silicon System

The chemical processes occurring during the interaction of carbon (diamond) with silicon are experimentally investigated. Thermal analysis of the interaction of diamond with silicon is carried out. This made it possible to determine the mechanism of the synthesis of silicon carbide and subsequent reaction sintering of diamond particles based on Turing’s reaction-diffusion process and the formation of a microstructure consisting of triple periodic surfaces of the minimal energy.

Model and Results of a Study of the Synthesis of Finely Dispersed Silicon Carbide in an Electro-Thermal Reactor

The high-temperature synthesis of silicon carbide (SiC) in an electro-thermal fluidized bed reactor (EFB) has advantages, in comparison with the production in resistance furnaces, in terms of specific energy consumption, productivity and the level of automation of the technological process. The basic equations of the fluidized-bed carbide formation process model are presented in the paper. The results of calculating the synthesis parameters of finely dispersed SiC in the stationary operation mode of the EFB reactor are also presented. The correspondence between the calculated and available experimental results on the output of the final product is shown.

Synthesis of silicon carbide in arc discharge in fuel oil

In this work, an experimental physical setup is proposed and a method for the synthesis of silicon carbide in an electric arc drowned into the thickness of hydrocarbon raw materials is described. Silicon carbide and carbon nanotubes were found in the deposits at the cathode. The resulting sample was analyzed using an optical microscope. And also confirmed the hardness of silicon carbide.

Selecting the Appropriate Carbon Source in the Synthesis of SiC Nano-Powders Using an Optimized Fuzzy Model

In this study, different sources of carbon in the synthesis of silicon carbide were evaluated using a multi-attribute group decision-making fuzzy model including IF-MAGDM method. In this model, the aim was to find the carbon precursor which has the minimum price, highest carbon content, good water solubility, lowest synthesis temperature, and the optimum crystallite size. Based on the results obtained from mentioned method, sugar was the best candidate. Therefore, sugar was selected as the efficient carbon source in the synthesis of SiC, also tetraethyl ortho-silicate was used as the source of silicon. The synthesis temperature was 800 °C, which is a relatively low temperature for the synthesis of crystalline SiC. To optimize the carbothermal process, microwave heating and just 15 min were enough to form crystalline SiC nanostructures. Various analyses were used for efficient characterize of the products. TGA-DTA were used to investigate thermal behaviours of the samples. XRD results showed that the SiC powder prepared by microwave heating was fully crystalline phases. FE-SEM and TEM analyses showed the nanometric nature in average particle size distributions of products with a flake-like morphology.

Green Synthesis of Silicon Carbide from Sugarcane Bagasse through Magnesiothermic Reduction: A Potential Biomaterial for Photovoltaic Solar Cell

Sugarcane bagasse is the most abundant agricultural waste in terms of tonnage in the Philippines. This biomass can be converted into silicon carbide (SiC) – an important material for photovoltaic (PV) cells. SiC was prepared at 600 °C for 4 hours with the use of magnesium powder as a catalyst and it was further enhanced by doping through the solvothermal method. The successfully synthesized SiC appeared grayish in color having an average yield of 8.56%. The SiC was doped with varying amounts of urea (0.1, 1.0, 2.0, and 3.0, 0.02 M), an n-type dopant, and carried out in triplicate basis. Incorporation of n-type dopants increased its capability to be a good built-in voltage and absorbent of light. Effective band-gap energies of semiconductor material for the PV cells were in the range of 1.0-1.7 eV. Urea-doped SiC exhibited a higher wavelength compared with undoped SiC, which could imply their differences in bandgap. The conductance testing showed that electrical conductivity established a positive relationship with dopant concentrations. Appeared to be crystalline in nature, the surface morphology of doped and undoped SiC was determined through scanning electron microscope. The X-ray diffraction patterns confirmed the crystallinity of the synthesized material. The elemental analysis and vibrational frequencies through energy dispersive X-ray and Fourier transform infrared analyses proved the presence of silicon and carbon in the material. Therefore, sugarcane bagasse can be processed chemically to generate new products for solar cell applications employing simple and low-cost method.

Finely dispersed silicon carbide synthesis model in the electrothermal reactor with periodic batch loading

Fine silicon carbide is used in metallurgy, electronic devices and the aviation industry. Reactors where the synthesis of finely dispersed carbides is organized in an electrothermal fluidized bed (ETKS reactors) have several advantages over resistance furnaces used for mass production of carbides. The basic advantage is the direct production of a finely dispersed fraction of carbide-containing particles with lower specific costs of electric energy. In this article, there were studied non-stationary processes in an ETKS reactor operating in the mode of periodic loading into the reaction volume of components of chemical reactions for the synthesis of silicon carbide: finely dispersed carbon-containing particles and SiO2 particles (batch). A mathematical model of synthesis for non-stationary conditions is developed. Relations are obtained for calculating changes in the process of silicon carbide synthesis not only of the sizes of solid (liquid) particles participating in chemical reactions, but also of the concentrations of volatile components that affect the rates of these reactions in the working volume of the ETKS reactor. There were carried out calculations to identify the influence of determining factors on the yield of the final product and the analysis of these results. A comparison of the calculation results with the available experimental data on the yield of silicon carbide in an ETKS reactor with a periodic charge loading was presented.

Анализ эпитаксии карбида кремния из газовой фазы как базового процесса в техно-логии силовой электроники. Обзор

Currently, chemical gas deposition is the main method for producing high-quality and reproducible epitaxial layers for commercial silicon carbide (SiC) power devices. Based on the experience of ETU «LETI» in the synthesis of monocrystalline SiC, an analysis of the current state of silicon carbide gas phase epitaxy (CVD) technology was carried out. It has been shown that modern CVD reactors allow to implement the growth processes of SiC epitaxial structures of high quality with the following parameters: substrates diameter up to 200 mm; thicknesses of epitaxial layers from 0.1 to 250 μm; layers of n - and p -types conductivity with ranges of doping levels 10-10 cm and 10-10 cm, respectively. At the same time, setting up the technology of the reproducible high-quality growth of epitaxial layers is an individual task for a specific type of reactor. It requires a detailed consideration of the technological factors presented in this paper, which at the end determine the achievable parameters of SiC-epitaxial products

Single-step synthesis of silicon carbide anchored graphitic carbon nitride nanocomposite photo-catalyst for efficient photoelectrochemical water splitting under visible-light irradiation

Visible-light active, silicon carbide (SiC) anchored graphitic carbon nitride (g-CN) nanocomposites (g-CN-SiC), with different SiC concentrations were synthesized using pulsed laser ablation in liquid (PLAL). Initially g-CN was synthesized by simple thermal pyrolysis, and subsequently SiC was loaded on the g-CN polymer network by PLAL to obtain g-CN-SiC polymeric-inorganic nanocomposites. The proper formation of g-CN-SiC nanocomposites is proven by XRD, SEM, TEM, and the elemental composition and the variation of elemental peaks in the nanocomposite due to the change of chemical environment was studied by XPS analysis. The synthesized g-CN-SiC were tested for their applicability as a catalyst in the process of photo-electrochemical water splitting for hydrogen production, a simple step ahead towards the realization of energy efficient fuel cells. The hydrogen production was quantified by measuring photocurrent density in the linear sweep voltammetry, and it was found that when g-CN-SiC is used in the photoanode, the measured photocurrent is consistently more than that produced by g-CN photoanode, with the highest observed photocurrent density for g-CN-SiC with 10 % SiC content, accounting for a seven-fold increase of photocurrent compared to pure g-CN. Enhanced visible light absorbance, and reduced photo-generated charge recombination in g-CN-SiC, observed in the absorption and photoluminescence spectra respectively can be attributed to the improved photo electrochemical activity of g-CN-SiC based photoanode in the process of water splitting.

Boron-doped silicon carbide (SiC) thin film on silicon (Si): a novel electrode material for supercapacitor application

In this work, we report the synthesis of silicon carbide (SiC) thin film on silicon by modified chemical vapour deposition technique using boron-doped liquid polycarbosilane as a precursor. Subsequent microscopic and physical characterizations of this film show the presence of SiC nanocrystal along with boron in the SiC thin film. The electrochemical characterizations of the film shows a highest capacitance of 232F/g at 2.2A/g current density from Galvanostatic charging–discharging method with good cyclic stability upto 2000 cycles. The high capacitance value is attributed to the surface defect states and amorphous carbon which acts as the charge active sites. The result further infers that the (B)SiC/Si is a promising electrode material for high-performance energy storage application.

Synthesis of silicon carbide from rice husk

Abstract This is a study about the synthesis of SiC from rice husk. The SiC production was carried out in two stages, the first one being the rice husk carbonization under vacuum, at the temperature range from 270 to 650 °C, and the second stage was the pyrolysis of the carbonized rice husk, at the temperature range from 1300 to 1800 °C and 120 min isotherms. The rice husk was characterized by X-ray fluorescence, and the reaction products were characterized by X-ray diffraction and scanning electron microscopy. The temperature influence on pyrolysis was demonstrated. SiC formation occurred in samples treated over 1600 °C, while at lower temperatures, it was possible to observe the secondary formation of cristobalite, tridymite, and quartz. In this study, it was possible to calculate the yield of SiC production as a function of the pyrolysis temperature of the carbonized rice husk.