High Performance SiC Research Articles

High-performance single SiC nanocable-based plasmonic photodetectors for ultraviolet communication systems

High-performance single SiC nanocable-based plasmonic photodetectors for ultraviolet communication systems

High-performance cobalt-embedded SiC nanofiber fabric for microwave dissipation

The incorporation of magnetic ingredients is critical for ceramic-based microwave absorbers with high efficiency. However, this task is becoming challenging due to the dispersion and oxidation issues. In this study, metal-organic framework (MOF) ZIF-67 was employed as the precursor of magnetic compounds and combined with a polymer solution to fabricate SiC textiles using the electrospinning technique. The microstructure analysis confirmed the successful introduction of MOF particles within the SiC nanofibers. Further examination of chemical compositions and magnetic properties revealed the encapsulation of magnetic compounds in hybrid SiC textiles. Since the applied fabrication approach ensures a superior dispersion and protection of metal compounds in a ceramic matrix, the microwave absorption of SiC fabric with both dielectric loss and magnetic loss exhibits a high reflection loss of -59.4 dB and a wide effective absorption band of 5.70 GHz. The current fabrication strategy for fabricating microwave absorbers with dual loss mechanisms advances the development of ceramic-based microwave absorption materials.

Hot oscillatory pressing of SiC ceramics with B4C and C as sintering additives

SiC ceramics with 0.5 wt.% B4C and 0.5 wt.% C as sintering additives were prepared by hot oscillatory pressure (HOP) and hot pressure (HP). The mechanical properties and microstructures of the resultant ceramics were investigated. The results showed that the oscillatory pressure could effectively suppress the abnormal growth of SiC grains and promote the formation of high-density dislocation and stacking faults. The hardness of SiC ceramics made by HOP at 2000oC reached 28.9 GPa, which was much higher than that (26.8 GPa) of the sample made by HP at the same temperature. The current study suggests that HOP is a promising technique for preparing high-performance SiC ceramics.

Ultrahigh growth rate-induced thick 3C-SiC heteroepitaxial layers on 4H-SiC and its oxidation characteristics

The cubic 3C-SiC displays unique advantages in power electronics applications due to its high channel mobility and low SiO2/3C-SiC interface state density. Therefore, the epitaxial growth technology of 3C-SiC is one of the core technologies for preparing high-performance SiC power devices. In this work, we choose 4H-SiC as substrates to grow 3C-SiC with methyltrichlorosilane (MTS)-H2 complex precursor and acheieved an ultrahigh epitaxial growth rate up to 278 μm/h. Then the oxidation treatment has been conducted. The elemental composition, surface morphology, and crystalline phase of the prepared 3C-SiC/4H–SiC thick films were comprehensively characterized with SEM, Raman, XRD and TEM techniques. The growth mechanism and oxidation characteristics of the 3C-SiC/4H-SiC heteroepitaxial layers were analyzed based on experimental phenomena.

Synergistic design of C/SiC@SiC aerogel for enhanced thermal insulation and electromagnetic wave absorption

High-performance SiC aerogels are sought after for their superior thermal insulation and absorption properties, especially in applications such as electromagnetic stealth for aero engines and high-temperature radar stealth. However, achieving SiC aerogel with both temperature resistance and strong wave absorption while controlling their properties remains a significant challenge. This study investigates the influence of reactant concentrations on the structure, thermal insulation, and absorption performance of SiC aerogels synthesized via the sol-gel method. The aerogel synthesized with a n(C):n(Si) ratio of 1:2 showed superior thermal insulation. Additionally, it showed excellent electromagnetic wave absorption, with a minimum reflection loss of −53.80 dB at 6.16 GHz and a maximum effective absorption bandwidth of 3.10 GHz at a thickness of 2.40 mm. Furthermore, the maximum compressive strength of C/SiC@SiC reached 0.98 MPa, a notable improvement of 81.48 % compared to the pristine C/SiC matrix. The maximum effective absorption bandwidth of C/SiC@SiC was increased to 6.06 GHz at 2.35 mm, and the surface center temperature decreased from 183.1 °C for C/SiC to 130.1 °C for C/SiC@SiC. Overall, this study offers valuable insights into the development of advanced absorption and thermal insulation materials, providing a foundation for further research and innovation in this field.

Structural control and mechanical properties optimization of porous SiC foams with three-dimensional network structure

In this paper, a new process for preparing porous SiC foam with three-dimensional network structure is presented. A certain thickness of SiC coating is deposited on the surface of ultra-light carbon skeleton by CVD process, so as to achieve effective control of its structure and mechanical properties. The effects of CVD deposition time on the density, porosity and skeleton thickness rates of SiC foams were explored. By increasing the CVD deposition time, the structure of SiC foams can be effectively regulated, and the mechanical properties of SiC foams can be significantly improved. The porosity of the prepared SiC foam can be adjusted in a wide range (26.9%∼94.68%). When the density of SiC foam increases from 0.67 g/cm3 to 2.36 g/cm3, its bending strength increases from 27.4 MPa to 136.9 MPa, which is significantly improved. After high temperature oxidation treatment (800–1200 °C), the mechanical properties of SiC foam will be further improved. However, when the oxidation temperature reaches 1400 °C, its mechanical properties will be reduced. This research provides a new idea for the preparation of high-performance porous SiC ceramics, and lays a foundation for its structural design, manufacture and application.

Vat photopolymerization of large-aperture high performance SiC mirror through multiphase carbon infiltration modification

Vat photopolymerization technique (VPP) shows advantages in rapidly preparation of complex structure silicon carbide matrix composites (Si/SiC). However, compared with traditional preparation technology, the properties of Si/SiC prepared via VPP are insufficient due to the presence of residual Si and carbon. Herein, the reaction mechanism of Si and carbon were systematically studied. Multiphase carbon was introduced into porous SiC preform via carbon precursor infiltration pyrolysis (CPIP) and graphitization methods. The content of residual Si was significantly decreased after reactive melt infiltration (RMI), and the residual carbon was eliminated through partial graphitization of the carbon. The influence mechanism of the carbon content and crystallinity on the reaction process of Si and carbon was studied. It suggested that the diameter of capillary channel and crystallinity of carbon are the main factors affecting residual carbon content in the final body after RMI. The sample with multiphase carbon achieved the best performance after RMI. The residual Si content, bulk density, flexural strength and elastic modulus are 11.58%, 3.04 g/cm3, 280.09 MPa and 355.48 GPa. In addition, the lowest coefficient of linear expansion was 2.39×10−6 K−1. Finally, a large-aperture SiC mirror with a diameter of 500 mm was prepared. Therefore, this research lays a foundation for promoting the application of large-aperture Si/SiC prepared via 3D printing.

Preparation high-performance SiC ceramic reinforced with 3D hybrid graphene oxide-carbon nanotube by direct ink writing and liquid silicon infiltration

This paper proposes the preparation of a silicon carbide ceramic matrix composite toughened with three-dimensional graphene oxide-carbon nanotubes (3D GO-CNT) using direct ink writing and liquid silicon infiltration processes. The research focuses on the microstructure and mechanical properties of the composite, emphasizing the toughening impact of varied GO-CNT ratios. When the GO-CNT ratio was 1:2, the mechanical properties of the material were optimal, with a flexural strength of 337.4 MPa and a fracture toughness of 4.58 MPa · m1/2, which were enhanced by 40.9% and 34.7%, respectively, compared to that of the pure silicon carbide matrix. Graphene oxide and carbon nanotubes can act as dispersants for each other enabling them to be uniformly distributed in the matrix. Key toughening mechanisms include GO/CNT pull-out, multiple microcracks, crack bridging, deflection, and branching. This study promises to significantly improve the mechanical properties of 3D printed SiC composites, assisting their potential applications in aerospace engineering.

Sintering of silicomanganese slag-reinforced porous SiC ceramic membrane supports with high alkali corrosion resistance

Herein, we report the production of silicomanganese slag-reinforced porous SiC ceramic membrane supports with high alkali corrosion resistance through low-temperature sintering. The effects of the sintering temperature and particle size of the silicomanganese slag (SiMn-slag) on the properties of the membrane supports were studied. The optimal membrane support was obtained at 1150 °C with 20 μm SiMn-slag, which exhibited an open porosity of 41.03%, pore size of 3.15 μm, ultra-high pure water permeability of 120074.60 L·m−2·h−1·bar−1 and high bending strength of 43.18 ± 0.70 MPa. In addition to the excellent acid corrosion resistance, the prepared membrane support displayed high alkali corrosion resistance due to the neck connections that formed, comprising alkali resistant mullite, anorthite, and bustamite. This work is of great significance in guiding the production of high-performance SiC membranes at a low cost and offers a possible route for utilising solid waste as a value-added separation material.

Streamlining manufacture of high-performance SiC catalytic membrane using bifunctional precursors for multipollutant control

SiC catalytic membrane holds great promise in controlling high-temperature nitric oxide (NO) and particulate matter (PM), but its complex fabrication process limits its potential for practical application. We present a novel, rapid fabrication route, based on co-sintering and acid treatment (CSAT), for the fabrication of Co3O4-loaded SiC (A-Co-SiC) catalytic membranes. Our approach involves using functional activated carbons and Co2O3 for the simultaneous sintering of both the support and separation layers at a lower temperature. The CSAT approach eliminates particle penetration into the support layer and accelerates the generation of active Co3O4 nanoparticles on Co2SiO4. This reduces the number of fabrication steps from 9 to 5, resulting in over a 50% reduction in both energy consumption and sintering time. The resulting A-Co-SiC catalytic membrane exhibits remarkable gas permeance of 224.51 m3 m−2 h−1·kPa−1, superior NO oxidation efficiency (85% at 280 °C), and a high PM2.5 filtration efficiency of 99.97% - the highest simultaneous removal of NO and PM2.5 reported to date. The manufacturing method developed in our work offers a practical and efficient solution for producing SiC catalytic membranes that can be utilized in various integrated emission filtration systems in industrial settings, with the potential to be adapted to other ceramic systems.

Microstructure and properties of liquid phase sintered SiC ceramics fabricated via selective laser printing and precursor impregnation and pyrolysis

Selective laser printing offers distinct advantages for fabricating large-scale and complex-shaped SiC ceramic components. However, the high porosity and low strength exhibited by SiC green bodies manufactured by selective laser printing necessitate an efficient heat treatment method to improve density and strength. This study presents an efficient technique for preparing SiC ceramics using selective laser printing coupled with precursor impregnation and pyrolysis (PIP) and liquid phase sintering (LPS). To enhance the density of the green body, a particle gradation technique was employed. Subsequently, a selective laser printing-powder, comprising SiC, Al2O3, Y2O3, and phenolic resin, was utilized to obtain a green body with a tailored microstructure. Following selective laser printing, SiC ceramics with flexural strength of 150 MPa and relative density of 98.2 % were produced by precursor impregnation and pyrolysis, followed by pressureless sintering. The outcomes of this study demonstrate a viable strategy for fabricating high-performance SiC ceramics via selective laser printing.

Low-temperature sintering of multifunctional SiC catalytic membrane for synergistic emission control of toluene and dust

SiC catalytic membranes have shown great potential in dust and atmospheric pollutant emission control. However, their high sintering temperature (up to 1850 °C) and the ‘trade-off’ effect between its gas permeance and catalytic performance have hindered their widespread application. In this study, a high-performance CuO-loaded SiC catalytic membrane was fabricated to address the above issues using a liquid phase sintering and surficial reconstruction (LSSR) strategy. The low melting point of CuO enables the liquid phase sintering of CuO-SiC membrane at a significantly reduced temperature of 1040 °C, and the formation of CuO nanoparticles (CuO-NPs) on bulk CuO in CuO-SiC membrane (CuO-NPs/CuO-SiC) is achieved through a surficial reconstruction process. The resulting CuO-NPs/CuO-SiC catalytic membrane exhibits a high gas permeance of 275.8 m3·m−2·h−1·kPa−1 and a bending strength of 14.2 MPa. The CuO-NPs/CuO-SiC catalytic membrane also displays complete (100 %) toluene oxidation and PM2.5 filtration efficiencies at 280 °C, as well as enhanced water vapor resistance and long-term stability. The LSSR was successfully applied to fabricate an CuO-NPs/CuO-Al2O3 catalytic membrane, which shows complete toluene oxidation and PM2.5 filtration efficiency at 300 °C, demonstrating that LSSR is readily extended to fabricating other ceramic and metal-ceramic-based catalytic membranes.

High-strength and low-silicon SiC ceramics prepared by extrusion molding 3D printing

Material extrusion is a promising additive manufacturing technique for fabricating high-performance SiC composites with complex structures. In this work, a novel strategy for fabricating SiC composites via material extrusion combined with solvent debinding and gaseous-liquid two step silicon infiltration was developed. The mixture used for material extrusion was composed of an organic binder, such as high-density polyethylene, ethylene vinyl acetate, paraffin wax and a C/SiC inorganic powder. The experimental results revealed that 89 wt% of the soluble components could be removed after debinding at 40 °C for 10 h in kerosene solvent, and the morphology was satisfactory after subsequent thermal debinding. After reactive sintering, the density of the SiC composite reached 3.12 ± 0.02 g/cm3, with a theoretical residual silicon content of 10.13 vol%. The flexural strength and elastic modulus reached the maximum values of 465 ± 35.35 MPa and 425 ± 11.78 GPa, respectively.

Design and simulation of 4H-SiC low gain avalanche diode

In the applications of nuclear and high-energy physics, Silicon Low Gain Avalanche Diodes (Si LGAD) as particle detectors have been shown to perform well in time resolution. Compared with silicon, 4H Silicon Carbide (4H-SiC) has a wider band gap, better radiation resistance, higher saturated carrier velocity and lower temperature sensitivity. Therefore, 4H-SiC LGAD is suitable for the detection of Minimum Ionization Particles (MIPs) under extreme radiation and temperature. However, due to the complexity of SiC device design and production, high performance SiC LGAD devices have not yet been produced. In this work, we use TCAD tools to design and simulate two n-type 4H-SiC LGAD structures with different electric field profiles, I/V and C/V characteristics and gain efficiencies. Through the analysis of simulation results, the LGAD with a triangle electric field profile in the gain layer has a higher gain efficiency, while the design with a trapezoid electric field profile is less affected by the gain layer thickness and more stable at high temperature. Subsequently, we will develop a set of SiC production processes under the guidance of this work.

High Performance SiC Power Module Based on Repackaging of Discrete SiC Devices

Increased adoption of electric vehicles (EV), photovoltaic (PV), and battery energy storage systems (BESS) is driving the need for high-current SiC power modules. The state-of-the-art multichip module is substantially more expensive than the IGBT module. This paper proposes a cost-effective packaging methodology for high-power SiC intelligent power modules (IPMs) with discrete SiC devices. The proposed IPM integrates the gate drivers, decoupling capacitors, snubbers, discrete SiC devices, direct bond copper (DBC), base plate, temperature sensors, and overcurrent protection circuits, achieving very low loop inductance and thermal resistance, and more than 50% cost reduction. A 1200V/480A/2.15mΩ half-bridge IPM is presented for comparison with commercial counterparts. A 1200V/240A/4.3mΩ six-phase IPM is developed, and its performance is experimentally verified.

Non-destructive identification of edge-component burgers vector of threading dislocations in SiC wafers by birefringence imaging

Non-destructive characterization of crystalline defects in SiC wafers is important for manufacturing high-performance SiC power devices with high productivity. The present study shows that the edge component of the Burgers vector can be identified by birefringence imaging under conditions deviating slightly from the crossed-Nicols condition and by calculation of the in-plane shear stress distribution. It is also found that the combination of birefringence observation and X-ray topography allows the discrimination of the family of threading screw dislocations. The present results will further the understanding of the relationship between defect structure and the properties of SiC power devices.

Preparation of SiC ceramics reinforced with in-situ generated mullite by microwave sintering

Combining mullite with SiC ceramics is considered to be an effective method to reduce the sintering temperature of ceramics while maintaining excellent performance of the resultant materials. However, traditional heating methods used in this process are still more energy intensive. This work presents a fabrication method for producing mullite-bonded SiC ceramics via microwave heating and an in situ mullite reaction bonding. Via the proposed method, the preparation of samples with a bending strength of 125 ± 6 MPa and a porosity of 36.2% can be achieved at 1200 °C for 15 min. The microwave coupling effect and the impedance matching effect of SiC particles provide the heat source for the rapid sintering of the mullite-bonded SiC ceramics at low temperature. Bridging configuration of mullite between SiC particles occurred due to the unique coupling effects during microwave heating. Moreover, the low sintering temperature and short holding time inhibit the formation of the detrimental cristobalite phase. This work indicates that this rapid and low-temperature preparation method of mullite-bonded SiC ceramics has potential uses in the industrial production of high-performance SiC ceramics.

Synthesis of Polytitanocarbosilane and Preparation of Si–C–Ti–B Fibers

Continuous SiC fiber is a kind of high–performance ceramic fiber that combines many advantages, such as high strength, high modulus, high hardness and low density. It has excellent mechanical properties, high–temperature and oxidation resistance, which could be applied as essential reinforcement in advanced ceramic matrix composites (CMCs) in the fields of aerospace and advanced weaponry. Melt–spinnable polytitanocarbosilane (PTCS) is an important precursor, which can be used to prepare continuous SiC fibers through a precursor–derived method. In this work, low–softening–point polycarbosilane (LPCS) and tetrabutyl titanate were used to prepare polytitanocarbosilane with a ceramic yield of 67.5 wt% at 1000 °C. FT–IR, TGA, GPC, 1H NMR, 29Si NMR, and elemental analysis were used to analyze the composition and structure of the PTCS precursor. Finally, Si–C–Ti–B fibers with an average tensile strength of 1.93 GPa were successfully prepared by melt spinning, pre–oxidation, pyrolysis, and high–temperature sintering of the PTCS precursor. The strength retention rates were 71.5% and 79.8% after heat treatment at 1900 °C and 2000 °C under an argon atmosphere for 1 h, respectively. The strength retention rates of Si–C–Ti–B fibers are higher than those of commercial Hi–Nicalon fibers, Tyranno ZMI fibers and Hi–Nicalon S fibers. This work can lay a theoretical foundation and technical support for developing high-performance SiC ceramic fibers containing titanium and their ceramic matrix composites.

Reaction-bonded robust SiC ceramic membranes sintered at low temperature with coal gangue

Herein, we report an in-situ reaction-bonded SiC membrane sintered at low temperature using a solid waste (i.e. coal gangue) as the sintering aid to form strong neck connections. The effects of sintering temperature and coal gangue proportion on their properties regarding pore size, open porosity, bending strength and pure water permeability were investigated. The single-channel tubular SiC membrane sintered at 1300 °C with a coal gangue proportion of 12 wt% was optimal, exhibiting an average pore size of 2.78 μm, a open porosity of 47.08%, a bending strength of 34.01 ± 1.3 MPa and a high water permeability of 83967 L m−2 h−1 bar−1. The membrane could completely reject D50 = 0.87 μm SiC solids and presented a steady-state water permeability of 458 L m−2 h−1·bar−1. The SiC membrane could be regenerated through ultrasonication and its steady-state water permeability was almost unchanged for 3 cycles, proving its mechanical robustness. This work may appeal to the practical low-cost production of high-performance SiC membranes.

Stereolithography-based additive manufacturing of RB-SiC ceramics by a two-step sintering method

Digital light processing technology (DLP) is an effective method to manufacture ceramics with high precision. It is a big challenge to prepare SiC green body with high solid content by DLP method due to the limitation of high light-absorbance of SiC powder in stereolithograhy. Here, we present one novel route for DLP additive manufacturing of high-performance SiC ceramics by introducing low light-absorbance SiO 2 powders and a two-step sintering process including carbothermal reduction and reactive melt infiltration. As-prepared SiC ceramic exhibited higher flexural strength of 268.66 ± 10.19 MPa, compared with reported stereolithograhy-based SiC ceramics. This method demonstrates the potential of preparing SiC ceramic composites with high mechanical properties by stereolithography additive manufacturing.