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Slurry infiltration method has been widely used as a preliminary step in preparing dense and multifunctional fiber reinforced SiC ceramic matrix composites. However, the infiltration efficiency of slurry is low mainly due to its insufficient stability, specifically manifested as the limited weight gain of composite after slurry infiltration. The aim of this study is to improve the infiltration efficiency of slurry by improving its stability, while maintaining its low viscosity and high particle concentration. In this study, by adjusting the particle size, two SiC slurries with identical high particle concentration (50 wt.%) and similar low viscosities (less than 10 mPa·s) but different stabilities were obtained and then applied in the infiltration process of composites. The stability of slurry can be highly improved by decreasing the particle size. The weight gain of composites after infiltration of high stability slurry (sedimentation time exceeding 35 h) is more than twice that of low stability slurry (sedimentation time nearly 1 h). Combined with chemical vapor infiltration method, the final composite using high stability slurry exhibits increased density, reduced porosity and enhanced mechanical performance. [ABSTRACT FROM AUTHOR]

The use of submicron silicon carbide powder as a raw material is crucial for preparing high-performance silicon carbide ceramics. However, its strong absorption of ultraviolet light makes stereolithography of submicron silicon carbide powder challenging. In this study, submicron SiC particles, photosensitive resin, and photoinitiator were used as raw materials to prepare SiC ceramics via stereolithography combined with a pressureless sintering method. The effects of ultraviolet wavelength, type, and content of photoinitiator on the curing properties of submicron SiC ceramic slurry were investigated. The results showed that the curing thickness of the SiC ceramic slurry significantly increased with the increasing ultraviolet wavelength. Compared to photoinitiators TPO and 396, photoinitiator 819 exhibited a better curing effect. Additionally, increasing the photoinitiator content facilitated the generation of more free radicals in the SiC ceramic slurry at low light intensity, thereby improving its ultraviolet absorption characteristics. When the dosage of photoinitiator 819 was 8.8 %, the SiC slurry achieved the best curing performance, with a single-layer curing thickness of 50 μm and a sintering density of 95 % for SiC ceramics. [ABSTRACT FROM AUTHOR]

As a kind of metal matrix composites, silicon carbide particulate reinforced aluminum alloy composites (SiCp/Al) have been widely applied in numerous fields. However, it is still difficult to process this composite material with electrical discharge machining (EDM) at present. To address this problem, this study introduces a novel rotary electrochemical discharge – chemical composite machining (RECDM-CM) method. This method uses rotating electrodes and workpieces to improve the flushing effect of working medium and utilizes the electrolysis to reduce the recast layer thickness. The chemical reaction between sodium carbonate (Na2CO3) and aluminum oxide (Al2O3) at high temperatures is used to remove the non-conductive Al2O3 in this composite machining. Rotary electrochemical discharge – chemical composite machining is used to process silicon carbide particulate reinforced AA2009 aluminum alloy composites with the silicon carbide volume fraction of 55%. The experimental results reveal that the material removal rate (MRR) of rotary electrochemical discharge – chemical composite machining is 5.2 times that of rotary electrical discharge machining, and its relative tool wear rate (RTWR) is 37.42% of rotary electrical discharge machining. The recast layer thickness is reduced to less than 13 μm via rotary electrochemical discharge – chemical composite machining. [ABSTRACT FROM AUTHOR]

This study investigates Beam Line Absorbers (BLAs) for the Hefei Advanced Light Facility (HALF). A ferrite-based BLA prototype was developed, demonstrating high-power handling capacity up to 10kW, ultra-high vacuum performance better than 6.5×10−10 mbar, and high absorption efficiency in critical frequency ranges. Subsequently, more compact designs with reduced longitudinal length were explored, investigating ferrite-only, silicon carbide (SiC)-only, and hybrid configurations through RF simulations. Based on preferred absorption efficiency, ferrite-only and hybrid BLA structures were further analyzed under high-power conditions. Referencing test results, multiphysics simulations were conducted under 3kW absorbed power. The hybrid design, comprising two rings of ferrite tiles and one ring of SiC tiles, improved the temperature distribution of the absorbing materials. Extrapolating to 11kW absorbed power, this design reduced the maximum temperatures on absorbing tiles by up to 40°C compared to the ferrite-only design. The hybrid design offers a balanced solution that combines effective HOM damping with enhanced thermal performance, improving the long-term operational stability of BLAs. [ABSTRACT FROM AUTHOR]

The top-seeded solution growth (TSSG) method is an emerging technique for the production of silicon carbide (SiC). Due to its advantage of lower growth temperature compared to the physical vapor transport method, it holds significant potential in the preparation of Al-doped SiC. In this study, a global numerical model calculating heat and mass transfer was established to investigate the impact of solution radius and height, coil position, and rotational speed of the seed crystal on the flow pattern and carbon transport. The results indicated that a meticulous determination of these growth parameters could enhance both carbon transport and growth rate. Furthermore, abundant transient calculation results were utilized to train back-propagation (BP) neural networks to extract the correlation between growth parameters, growth rate, and Al concentration. The optimal parameters were ultimately obtained using the non-dominated sorting genetic algorithm (NSGA-II). The Al concentration calculated in the solution under the optimal growth conditions demonstrated that the evaporation of Al was sufficiently low to satisfy the p-type doping requirement. This study provides valuable insights for the future development of a TSSG system tailored for the rapid growth of Al-doped SiC. [ABSTRACT FROM AUTHOR]

With careful design and integration, microring resonators can serve as a promising foundation for developing compact and scalable sources of non-classical light for quantum information processing. However, the current design flow is hindered by computational challenges and a complex, high-dimensional parameter space with interdependent variables. In this work, we present a knowledge-integrated machine learning framework based on Bayesian Optimization for designing squeezed light sources using microring resonators. Our model, after only 5 optimization rounds, identified two optimal structures with distinct cross-sectional areas and radii (65 and 110 ), achieving escape efficiencies over 90% and on-chip squeezing levels of 7.48 dB and 9.86 dB, respectively. Our results demonstrate that by adaptively finding the coupling coefficient through BO, the model has identified optimal points in the over-coupled regions with superior performance. This optimization model is developed specifically for single resonators made of silicon nitride. However, its applicability extends beyond this, and it can be used to model structures with auxiliary rings or other materials like silicon carbide. Our approach is expected to streamline the design of other integrated photonic components, including Mach-Zehnder interferometers and directional couplers, for applications in quantum photonic circuits and optical neural networks. [ABSTRACT FROM AUTHOR]

This study elucidates the characterization of silicon carbide fibers synthesized from a polymer blend comprising polycarbosilane (PCS) and polysilaethylene (PSE). Given that PSE lacks oxygen in its molecular structure and possesses a C/Si ratio of 1, akin to polymethylsilane (PMS)—which historically has been combined with polycarbosilane to enhance ceramic yields—it was anticipated that PSE would similarly augment the ceramic yield of the fibers post-pyrolysis. Unlike PMS, PSE exhibits compatibility with PCS up to 15 wt%, with a notable reduction in melt spinnable temperature when the PSE content surpasses 5 wt%. Fibers containing 5 wt% PSE, melt-spun at 603 K, developed a central hollow in the cross-section, attributed to hydrogen gas evolution from PSE. Incorporating 10 wt% or more PSE improved spinnability and facilitated the production of fibers with finer diameters. Ceramic yield after pyrolysis at 1273 K for 1 h was improved compared to fibers without PSE or with PMS, and after holding at 573 K for 2 h, the yield increased when subjected to an additional hold at 573 K for 2 h, due to an increase of cross-linking in the samples. [ABSTRACT FROM AUTHOR]

In the present work, investigations of the wettability, wear, and morphological study on 3D-printed polylactic acid (PLA)/molybdenum disulfide (MoS2)-silicon carbide (SiC) based composite have been performed. In the first stage, the PLA/MoS2-SiC composite was fabricated from the different types of filaments of 1.75 ± 0.10 mm size by taking MoS2-SiC as reinforcement at various extrusion temperatures (150°C–160°C) and screw rotational speed (3–7 r/min) of the extruder setup. The Taguchi L9 orthogonal array was used to design the experiments for 3D printing by varying the filament type, range of nozzle temperature (200°C–210°C), and infill density (40%–90%). The pin-on-disk (POD) setup was used for measuring specific wear rate (SWR) and showed the lowest value of 0.00141 g/N-m when composites were 3D printed by taking filaments manufactured at the parametric combination of 160°C extruder temperature and 7 r/min rotational speed, while 3D printed at 210°C nozzle temperature and 40% infill density. Contact angle (CA) values indicated that the reinforcement of MoS2 and SiC in PLA resulted in hydrophilic surface formation due to morphology and increased roughness (including mean roughness (Sa), mean root square of the Z data (Sq), and the highest peak (Sz)). The significantly increased surface free energy (SFE) of MoS2-SiC-reinforced PLA composite compared to pure PLA was reported which makes the prepared composite a promising candidate to be used for biocompatible implants with high wear resistance. [ABSTRACT FROM AUTHOR]

Ceramic saggars of mullite‐cordierite are currently used to produce cathode powders for lithium‐ion batteries. Strong interactions occur between the LiNi0.8Mn0.1Co0.1O2 (NMC) precursor in the temperature range of calcination (750–1000°C) leading to corrosion and formation of cracks in the saggar. The frequent failure of saggar causes a lot of waste, which could be reduced by choosing corrosion‐resistant materials. To understand the corrosion mechanism in the system MgO–Al2O3–SiO2, the materials MgO, Al2O3, MgAl2O4, and SiC (instead of SiO2) were embedded in premixed NMC precursor and calcined at T = 780°C for 50, 100, 150 and 200 h. The formed phases were determined by phase and microstructure analysis. Finally, the formation of LiAlO2 and Li5AlO4 is associated with a lower growth rate of the corrosion layer compared with Li4SiO4, while MgO is inert. The reactivity with NMC can be ordered as follows: SiO2 > Al2O3 > MgO. [ABSTRACT FROM AUTHOR]

Vat photopolymerization (VPP) printing of ceramic parts offers advantages such as low cost, simple operation, and short fabrication cycles. However, drawbacks include low toughness and brittleness in the printed parts. This study explores enhancing the toughness and strength of alumina (Al2O3) ceramics by incorporating silicon carbide (SiC) particles as additives. The impact of varying SiC contents on the quality of VPP‐printed Al2O3 parts is examined, encompassing microstructure, physical properties, and mechanical properties. Results indicate that optimal SiC addition reduces Al2O3 ceramics' porosity, enhances crystalline quality, and boosts mechanical properties. Excessive SiC, however, diminishes these benefits. The most significant strengthening of Al2O3 parts occurred with a 1.5 wt.% SiC content, increasing bending strength and fracture toughness by 239.7% and 564.7%, respectively. This underscore SiC's positive role in enhancing the quality of VPP‐printed Al2O3 parts. [ABSTRACT FROM AUTHOR]

In this study, silicon carbide (SiC) was prepared from sol–gel process combined with subsequent carbothermal reaction. Then through hydrothermal method synthesized xFe/SiC-700 and 30Fe/SiC-T catalysts. The catalysts were characterized by XRD, SEM/TEM, XPS, and H2-TPR. The ammonia decomposition performances of the catalysts were assessed in a fixed-bed reactor. Tests revealed that SiC has a high specific surface area and can evenly diffuse Fe2O3 nanoparticles, thus exposing more active sites and raising the adsorption capacity of catalysts surface. The interaction of Fe2O3 and SiC is stronger, the catalyst activity is better. The surface basicity of catalyst is higher, decomposition ability of ammonia is stronger. 30Fe/SiC-700 catalyst has the best activity among the synthesized catalysts for hydrogen production by ammonia decomposition. The ammonia conversion rate can reach up to 90.16%, and the hydrogen generation can rate reach up to 30.19 mmol·min−1·gcat−1 at 600 °C at 30,000 mL·gcat−1·h−1. Moreover, the catalytic activity is efficient and stable after continuous reaction at 600 °C for 160 h. Ammonia decomposition: The silicon carbide supported iron oxide catalyst was prepared, which effectively cracked ammonia to produce COX-free H2. [ABSTRACT FROM AUTHOR]

The corrosion behaviour of 6061 Al-10(vol.%) SiC(P) composite in hydrochloric acid (HCl) was studied. Studies were done in 0.01 and 0.025 M HCl using 1-methyl-1-propyl piperidinium bromide (MPPB) as a green inhibitor. Potentiodynamic polarisation (PDP) and electrochemical impedance spectroscopy (EIS) were conducted at the temperature range of 303 K–323 K. Kinetic parameters were calculated and results were fitted into suitable adsorption isotherms. Adsorption/desorption equilibrium constant was used to evaluate, the thermodynamic parameters. Surface analysis was done by different methods such as scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), and atomic force microscope (AFM). The highest efficiency was found to be 77.49% in 0.01 M HCl and 72.89% in 0.025 M HCl for 400 ppm of inhibitor at 303 K. As the concentration of acid increased, inhibition efficiency decreased. Inhibitor acted as a mixed type, adsorbed physically onto the metal surface, and followed Langmuir adsorption isotherm. [ABSTRACT FROM AUTHOR]

We have reported that hydrogen or helium ion implantation can suppress the expansion of stacking faults in SiC devices. These results suggest that point defects caused by ion implantation are an important factor in suppressing the expansion. On the other hand, the depth distribution of point defects introduced by implantation of these ions has not been fully elucidated. In this study, we evaluated the point defect and carrier lifetime distributions inside SiC diodes implanted with hydrogen or helium ions by cathodoluminescence and microscopic free carrier absorption methods. [ABSTRACT FROM AUTHOR]

The sintering of ZrB2 presents significant challenges due to its covalent bonding and the high temperatures required for the process. Prior research has demonstrated that incorporating up to 20% by volume of SiC as an additive can enhance both the sintering process and the mechanical properties of ZrB2-based composites. The objective of this study was to fabricate and characterize an ultra-high temperature ceramic composite composed of ZrB2 containing 20 vol. % SiC, utilizing the Spark Plasma Sintering (SPS) method with a multi-step approach at various temperatures. Additionally, the study sought to investigate the influence of a TiC additive on the microstructural evolution and mechanical properties of the composite. The research focused on assessing the impact of sintering temperature, ranging from 1600°C to 1900°C under a pressure of 30 MPa, in the presence of a 10 vol. % TiC additive. The introduction of up to 10% by volume of TiC into the ZrB2-20 vol. % SiC composite, followed by sintering at 1800°C for 5 minutes, resulted in the formation of (Zr,Ti)B2 and (Ti,Zr)C solid solutions within the matrix. These solid solutions, along with reactions involving surface oxides such as ZrO2 and B2O3, contributed to a 15% increase in relative density. Furthermore, notable enhancement was observed in the mechanical properties, including a 14% increase in hardness, a 12% increase in elastic modulus, a 20% increase in fracture strength, and an 8% increase in fracture toughness. A comparative analysis with previous studies revealed that employing a multi-step SPS technique, as opposed to a single-step process, significantly reduced the temperature and time of the process to achieve a relative density exceeding 99%. However, it was also observed that increasing the maximum sintering temperature to 1900°C in the ZrB2-20 vol. % SiC-10 vol. % TiC composite resulted in excessive grain growth and a slight decrease in relative density by approximately 1%. [ABSTRACT FROM AUTHOR]

The third-generation semiconductor silicon carbide (SiC) has attracted widespread attention due to its excellent properties, such as high thermal conductivity, large bandgap, high breakdown field strength, and high saturation electronic drift rate, etc. Consequently, the growth process, physical structure, and properties of SiC crystals have also become research hotspots in industry and academia sectors. With the concept of carbon peak and carbon neutrality, the photovoltaic industry has witnessed rapid development. In the process of silicon wafer production, nearly half of the crystalline silicon is lost in the form of silicon powder into silicon cutting waste (SCW), which results in a great waste of resources and severe environmental pollution, and therefore the use of SCW for the preparation of SiC materials has received great attention in recent years. This paper highlights the principles and methods of SiC growth, crystal structure and properties, and discusses the application of SiC prepared from SCW.

This study examines the reliability of several electronic components in a Vienna Rectifier configuration, which is a critical topology for power conversion systems. Component selection has become increasingly important over the past few years since the power electronics of today demand more efficiency, power density, and operational reliability. Extreme reliability testing such as temperature cycling, electrical overload, and long duration of high-frequency operation was a part of the study. GaN MOSFETs had an edge over Si and SiC MOSFETs in several aspects, such as decreased conduction and switching losses, better thermal management, and more consistent performance with time. While GaN MOSFETs performed better in general and especially at high frequencies and temperatures, SiC MOSFETs showed some improvements over the conventional Si devices. Capacitors, diodes, MOSFETs, and inductors are put to test for reliability under different stress conditions. The combination of diodes and GaN MOSFETs showed a synergistic effect in improving system dependability and reducing temperature-induced degradation. This is a significant result. The combined effects allowed active and passive parts to last longer and function more reliably. These results open insights into selecting components for systems in the automotive and aerospace industries, which mostly rely on reliability.

For many synchrotron radiation experiments, it is critical to perform continuous, real-time monitoring of the X-ray flux for normalization and stabilization purposes. Traditional transmission-mode monitors included metal mesh foils and ionization chambers, which suffered from low signal stability and size constraints. Solid-state detectors are now considered superior alternatives for many applications, offering appealing features like compactness and signal stability. However, silicon-based detectors suffer from poor radiation resistance, and diamond detectors are limited in scalability and are expensive to produce. Silicon carbide (SiC) has recently emerged as an alternative to both materials, offering a high-quality mature semiconductor with high thermal conductivity and radiation hardness. This study focuses on a systematic exploration of the SiC `free-standing membrane' devices developed by SenSiC GmbH. In particular, we performed in-depth sensor-response analysis with photon energies ranging from tender (1.75 keV) to hard (10 keV) X-rays at the Four-Crystal Monochromator beamline in the PTB laboratory at the synchrotron radiation facility BESSY II, studying uniformity of transmission and responsivity compared with the state-of-the-art beam monitors. Furthermore, we theoretically evaluated the expected signal in different regions of the sensors, also taking into account the effect of charge diffusion from the SiC substrate in the case of the not-carved region.

Silicon carbide is a chemical compound known for its high mechanical strength and exceptional thermal resistance. However, its synthesis typically necessitates very high temperatures and involves complex manufacturing techniques. Consequently, numerous studies have sought to lower the synthesis temperature of SiC by employing biomass-derived precursors. Despite these efforts, the efficiency of the SiC synthesis reaction remains low, resulting in suboptimal production yields. This study examines the impact of additives, specifically magnesium and copper, on the formation of SiC . Differential Scanning Calorimetry analysis of the mixtures indicates magnesium additives can facilitate earlier SiC formation compared to copper ( 466.73◦C vs. 522.02◦C ). According to ISO 20068:2008 standards for SiC composition determination, at a sintering temperature of 1000◦C, copper additives are more effective in generating SiC than magnesium. Analysis of SiC composition and X-ray diffraction patterns reveals that magnesium and copper additives significantly enhance the quantity of SiC produced. However, these additives also introduce numerous impurities into the final product. These impurities can be mitigated through acid washing.

SiC-based n-channel and p-channel MOSFETs fabricated by Fraunhofer IISB SiC CMOS technology are characterized from room temperature up to 300°C. The behaviors of these low voltage devices including the short-channel effect (SCE), p-type ohmic contact with high resistivity, and the low channel mobility due to the SiC/SiO2 interface are presented. A thorough analysis is performed to understand the cause of low channel mobility, with TCAD simulations specifically on p-channel MOSFET, providing an insight into the impact of channel length, interface traps, and contact resistivity on device performance. The analysis in this paper is important in the comprehension of the low-voltage SiC MOSFETs so as to achieve balanced n-channel and p-channel MOSFETs and lead to the monolithic integration of SiC ICs with SiC power devices.

[Display omitted] • A bifunctional SiC membrane with long-term oil filtration ability was prepared. • PDMS modified TiO 2 endow the SiC with optimal catalytic and antifouling property. • The well loaded modification layer has good binding force and thermal stability. • The membrane shows excellent oil filtration efficiency and long-term use capacity. Oily aerosols as the most adhesive particles in the air can cause irreversible fouling of filters. Amphiphobic surface of filters can to some extent reduce membrane fouling, but complex oil fouling will still adhere to the membrane surface, leading to a decrease in membrane separation performance over long-term use. Herein, a silicon carbide (SiC) membrane with amphiphobic properties and catalytic functions was developed to collaboratively combat pollution. Low surface free energy 1H,1H,2H,2H perfluorooctyltrichlorosilane (FOTS) monomer and TiO 2 nanoparticles were individually applied to the SiC membrane. PDMS was utilized to protect the monomer from degradation by the catalyst. The membrane exhibits good anti-adhesion and photocatalysis performance for oily aerosols. The membrane exhibits excellent oily aerosol filtration efficiency (98.6 %) with a comparative low filtration resistance of 6.4 kPa, as well as a high capacity for regeneration. Under UV light, the membrane can degrade oily fouling to recover its amphiphobic property. After 5 cycles of filtration, it still maintains good repeatability for oily matter separation and degradation. This study offers a practical approach to designing a membrane that enables long-term and efficient cleaning of oily aerosols. [ABSTRACT FROM AUTHOR]

• This grinding force model can provide guidelines for the research related to the force measurement when processing 2.5D C/SiC composites. • When V f / n is kept constant, the magnitude of the grinding force is unchanged. • The influence of ultrasonic amplitude on grinding force is lower than that of feed rate and grinding depth. • The measurement results showed that the average diameter of the abrasive grains is 0.035 mm with a deviation of 0.012 mm. In this work, a grinding force predictive model is proposed for processing 2.5D carbon fibre-reinforced silicon carbide matrix composites (C/SiCs) using ultrasonic-assisted end grinding (UAEG). The coupling effects of process parameters on prediction results are explored, and the influence of processing parameters on forces is analyzed from the theoretical perspective. In the modelling process, the anisotropy of the 2.5D C/SiCs, the motion path of the end-face grits, and the grit-workpiece interaction stages were fully considered. According to the material's removal properties, the interaction of the grit-workpiece was classified into different stages. The proposed model can be derived by considering the forces at different contact stages. To evaluate the model's reliability, single-factor experiments were conducted to assess its prediction accuracy. The results of validation with experiments demonstrated that the maximum error of the model was less than 12 %, and the average error was only 6.23 %. [ABSTRACT FROM AUTHOR]

The brittleness of silicon carbide restricts its wide application. Graphene as a superior second-phase material can improve the toughness and brittleness of silicon carbide. In this article, a graphene/β-SiC ceramic material was prepared with 1–3 wt.% graphene added in β-SiC matrix via pressure-free sintering at 2120°C for 60 min. The effect of the graphene addition on the phase composition, bulk density, porosity, and mechanical properties of ceramic material was investigated. The results show that the bulk density of graphene/β-SiC ceramic material decreases, the porosity of openings increases, and the bending strength, hardness, as well as fracture toughness firstly increase and then decrease as graphene addition increases. Compared with β-SiC ceramic without graphene, the optimum properties of graphene/β-SiC ceramic with graphene addition of 1 wt.% (i.e. a fracture toughness of 5.07 MPa m1/2, bending strength of 410.84 MPa and hardness of 27.72 HV) can be obtained, which are increased by 35.56%, 13.35%, and 3.8%, respectively. The fracture morphology indicates that the crack deflection is the main mechanism of toughening β-SiC ceramic with graphene. [ABSTRACT FROM AUTHOR]

• The minority carrier lifetime of different stacking faults in n-type 4H-SiC is studied. • A "step-structure" quantum well model for multi-stacking faults was proposed, taking into account the band bending by electron trapping in the stacking faults and electronic transitions between defect energy levels. • The carrier recombination at the SFs is discussed in terms of the accommodation ability of electrons inside the quantum wells. The effect of stacking faults (SFs) on carrier lifetime in 110 μm 4H-SiC epilayers has been studied using photoluminescence and microwave photoconductance decay. The carrier lifetimes are associated with different types of SFs. The SFs are distinguished as multi-SFs and mono-SFs in terms of their characteristic luminescence peaks. The average lifetime at multi-SFs is about 60 % of that at mono-SFs. Contrary to the quantum well models reported previously, multi-SFs decrease the minority carrier lifetime than mono-stacking faults even with shallower energy levels. A "step-structure" quantum well model is proposed to discuss the carrier dynamics for the enhanced recombination at the multi-stacking faults. [ABSTRACT FROM AUTHOR]

• MD simulations reveal intricate microstructural changes during SLM process. • Laser-induced melting forms continuous meltpools in SiC nano-powder beds. • Rapid solidification results in amorphous domains with fine-grained microstructures. • Meltpool overlap enhances bonding between nano-powders, reducing voids. • High thermal energy disorients atoms, reducing crystalline structures. Silicon carbide (SiC), with its isotropic three-dimensional diamond lattice structure, emerges as a promising candidate for SiC device production through selective laser melting (SLM). The appeal lies in its simplified fabrication process, coupled with outstanding thermal properties, high hardness, and remarkable wear resistance. This potential of SiC in SLM not only streamlines the fabrication process but also harnesses the exceptional properties inherent in SiC. In this study, we utilized molecular dynamics (MD) simulations to model the SLM process. A nanopowder bed made up of approximately half a million atoms of SiC was simulated as a two-layer quasi-2D system. Controlled heating of SiC meltpools, slightly surpassing the melting temperature, facilitated the monitored coalescence of nano-powders, resulting in successful melting and the formation of continuous domains within the meltpools. The observed reduction in crystalline structures is due to the elevated thermal energy imparted to the SiC atoms during the heating process, which disrupts the atomic arrangement and leads to a transition from crystalline to amorphous states. The subsequent solidification process, characterized by a high cooling rate, led to the establishment of final amorphous solidified domains. Looking ahead, our research aims to delve into exploring the structural and functional characteristics of the produced SiC devices, evaluating their potential applications across diverse technological domains. [ABSTRACT FROM AUTHOR]

The interface structure, micro-voids, pits, delamination, intermetallic compounds and internal stresses are the utmost critical factors influencing the corrosion performance of composite materials making them unsuitable for use in structural applications. One useful technique to control such adverse effect in composites is surface modification of the reinforcement. The present investigation involved the implementation of chemical techniques, particularly electroless plating (EP), to modify the surface of silicon carbide (SiC) particles by depositing a layer of nickel phosphorous (Ni-P) onto them. These plated SiC particles were subsequently employed in the production of Al/ Ni-p SiC composites using the powder metallurgy (PM) method, with different weight percentages of plated SiC content ranging from 5 % to 15 %. The corrosion behaviour was assessed by potentio-dynamic polarization tests in 3.5 % NaCl solution at room temperature. Results confirmed that Al Ni-p SiC composites exhibit a greater resistance to pitting, in contrast to pure aluminium and Al/SiC composites without plating. The enhanced corrosion resistance in Al/ Ni-p SiC composites can be attributed to strong interfacial bond, grain refinement, CTE difference, formation of Ni 3 Al, and reduced potential difference. • The surface of SiC particles was modified through the application of a Ni-P layer utilizing the electroless plating method. • The surface modified SiC particles were used to fabricate composites using the powder metallurgy technique. • Electrochemical polarization tests were performed on all samples to assess their corrosion behavior. • The findings indicated that composites reinforced with Ni-P plating demonstrate enhanced resistance to pitting. • The improved corrosion resistance can be ascribed to a robust interfacial bond, refinement of the grain structure etc. [ABSTRACT FROM AUTHOR]

The lifetime of electronic devices in complex environments is affected by the impact of high temperature water vapor on their performance. Equipping electronic devices with superhydrophobic properties and improved thermal conductivity will be the strategy of the future. In this paper, a surface material with high thermal conductivity and superhydrophobic properties is explored to address the problem of electronic device failure caused by heat and water vapor. To solve this problem, anti-temperature superhydrophobicity can be obtained by spraying alumina/nano-silicon carbide/thermoplastic elastomer composite powder (Al 2 O 3 /nano-SiC/SEBS) modified with 1 H,1 H,2 H,2H-perfluorooctyltriethoxysilane (POTS) on graphene membranes. A spherical Al 2 O 3 /nano-SiC composite superhydrophobic coating (ASS-GM) was formed on the surface of graphene-based composite membranes by spraying method. The results showed that the optimal ratio was m(Al 2 O 3): m(SiC) = 8:1, and the static water contact angle of the coating was 162 ± 2.5°, and the surface energy was reduced. The ASS-GM significantly improves the thermal conductivity and superhydrophobicity of graphene-based composite membranes, achieving a double improvement in performance. The coating also offers excellent self-cleaning and antifouling properties compared to other materials. The ASS-GM is able to maintain a certain hydrophobicity angle (156 ± 1.5°) in harsh environments. This work provides practical applications for electronic coatings, which are important for improving the overall reliability and durability of electronic products. [Display omitted] • A flexible multifunctional graphene-based composite membrane sample was obtained by SEBS-modified Al 2 O 3 /Nano-SiC. • This sample showed physical/chemical/mechanical stability in harsh environment. • The sample shows excellent thermal conductivity and superhydrophobic properties. • The sample shows excellent resistance to water spray condensation. • The sample shows excellent self-cleaning and anti-fouling properties. [ABSTRACT FROM AUTHOR]

[Display omitted] • SiO 2 layer of SiC particles can be used to reduce the carbon in PIP-SiC matrix. • SiO 2 -C reactions take place during the heat treatment at 1400 °C for 8 h. • Carbon reduction enhances the density and crystallinity of PIP-SiC matrix. • Open porosity arising from carbon loss should be sealed to finalize processing. Silicon carbide fiber (SiC f) reinforced/silicon carbide (SiC) matrix composites (SiC f /SiC) produced by polymer impregnation and pyrolysis (PIP) typically exhibit low density and crystallinity due to the formation of a SiC x O y amorphous matrix. This compromises the mechanical and thermal properties of the composites. Here, a particle enhanced PIP (PE-PIP) method is proposed whereby fine silicon carbide particles (SiC p) containing amorphous silica (SiO 2) layer are incorporated into the liquid poly (carbosilane) (PCS)-based precursor. The addition of SiC p improved the bulk density and decreased the open porosity of the composites compared to conventional PIP processing. After heat treatment at 1400 °C for 8 h, the true density of the composites was enhanced further with a reduced carbon content via the carbothermal reactions between SiO 2 and the excess carbon present in the PIP matrix. However, the bulk density reduced due to increased open porosity which could be sealed by subsequent processing. This novel processing approach has the potential to deliver high density, high crystallinity SiC f /SiC with low carbon content by PIP at low temperature (1400 °C). [ABSTRACT FROM AUTHOR]

This work investigates the ruggedness of paralleled silicon carbide (SiC) MOSFETs tested under unclamped inductive switching (UIS) conditions. More specifically, the maximum avalanche energy (E AV) sustainable by individual and paralleled MOSFETs integrated in a multi-chip power module (PM) is quantified. Circuital electrothermal (ET) simulations are carried out by resorting to a physics-based electrical model of a commercial SiC power MOSFET coupled with a dynamic thermal feedback block (TFB). The electrical model of the power MOSFET, accounting for temperature-sensitive parameters, was calibrated on measurements data of transfer /output characteristics and of UIS tests. The TFB was extracted using FANTASTIC, an advanced numerical tool based on a model-order reduction technique; it accounts for self- and mutual-heating of devices, including nonlinear thermal effects. A comprehensive analysis of the system ruggedness was performed by focusing on (i) mutual heating mechanisms between transistors and (ii) technological mismatches in breakdown voltage (BV). • We aimed to evaluate the ruggedness of parallel SiC MOSFETs under UIS conditions. • The effect of mutual heating between devices was investigated. • The impact of breakdown voltage mismatch was taken into consideration. • Electrothermal circuit-based simulations were conducted for this study. • The models were calibrated using experimental data. [ABSTRACT FROM AUTHOR]

• Study of structural, electronic and optical properties for tetragonal silicon carbide under biaxial tensile strain. • The photocatalytic properties for tetragonal silicon carbide improved under biaxial tensile strain. • The hydrogen production for tetragonal silicon carbide enhanced as function biaxial tensile strain. In this study, according to the density functional theory, we examined the optical, electrical, photocatalytic, and hydrogen production properties as a function of the strain of tetragonal silicon carbide (t-SiC). Our results showed that the tetragonal silicon carbide (t-SiC) has a bandgap of 3.23 eV according to the HSE06. In addition, the photocatalytic properties and hydrogen production for tetragonal silicon carbide (t-SiC) are improved under biaxial tensile strain, so at 8 % the value of hydrogen production is 23.23 104 µmol/g. Moreover, the band gap and the optoelectronic properties are altered by the application of strain. Our findings reveal that biaxial strain is used to change the electronic, optical, and electrical properties, with us identifying a decrease in the band gap as a function of the biaxial tensile strain applied to t-SiC. We predict that t-SiC under tensile strain and a suitable pH will be suitable for photocatalytic applications. [ABSTRACT FROM AUTHOR]

4H silicon carbide (SiC) has several advantageous properties compared to silicon (Si) making it an appealing detector material, such as a larger charge carrier saturation velocity, bandgap, and thermal conductivity. While the current understanding of material and model parameters suffices to simulate unirradiated 4H-SiC using TCAD software, configurations accurately predicting performance degradation after high levels of irradiation due to induced traps and recombination centers do not exist. Despite increasing efforts to characterize the introduction and nature of such defects, published results are often contradictory. This work presents a bulk radiation damage model for TCAD simulation based on existing literature and optimized on measurement results of neutron-irradiated 4H-SiC pad diodes. Experimentally observed effects, such as flattening of the detector capacitance, loss of rectification properties, and degradation in charge collection efficiency, are reproduced. The EH 4 center is suggested as a major lifetime killer in 4H-SiC, while the still controversial assumption of the EH 6,7 deep-level being of donor type is reinforced. [ABSTRACT FROM AUTHOR]

The Silicon Carbide (SiC) triplex cladding tube has been regarded as one of the leading structures for the next-generation light water reactors, because of its larger safety margins under beyond-design basis transient conditions. In this study, a numerical simulation method is developed to reproduce the damage and fracture behaviors of a nuclear-grade SiC triplex cladding tube during the burst test. Especially, a three-dimensional continuum damage mechanics based (CDM-based) constitutive model is developed and validated for the SiC f /SiC composites, with the predictions agreeing well with the experimental data under different loading conditions. By introducing cohesive surfaces in the monolithic layers of a SiC triplex tube, cracking of the monolithic layers and the subsequent local damage behaviors within the SiC f /SiC composite layer are captured. The local tensile strength of ∼402 MPa is identified for the monolithic layers, corresponding to the first load drop during the burst test. The simulation results indicate that cracking of the monolithic layers leads to sharp increases in the locally enhanced hoop stresses and damage factors for the SiC f /SiC composite layer, with slight influences on the field variables far away from the main crack; after the fast increase the evolution velocity of local damage factors slows down, reflecting the toughening effects of SiC f /SiC composite. An assessment strategy for the gas leak tightness and structural integrity of the SiC triplex cladding during the accident sceneries is proposed to predict failure of the SiC f /SiC composites with the critical damage factor, and it is necessary to simulate the damage and fracture behaviors in the multi-layer models with the cracking process of monolithic layers involved. [ABSTRACT FROM AUTHOR]

In this study, 500 keV He ions were used to irradiate CVD-SiC samples at 800 °C. The influence of doses on the microstructural evolution and hardness of the irradiated samples were investigated by TEM, Raman, and nanoindentation. TEM results show that He bubbles and dislocation loops appeared after irradiation, and their number densities increased with doses, resulting in the gradual decrease of the intensity of the TO peak in Raman spectra. Moreover, He platelets with strain field were observed in both stacking faults and matrixes. Nanoindentation results indicated that the irradiation hardening occurred, and the hardening degree was positively correlated with the irradiation dose. [ABSTRACT FROM AUTHOR]

• The irradiation effects on the interfacial strength of mullite and alumina double-layer coatings on SiC were investigated. • A transition layer, approximately 2 µm thick, formed at the SiC/mullite interface during the coating process. • The interfacial strength was evaluated following Si-ion irradiation using the microscale double-notch shear testing technique. • The strength of both the SiC/mullite and alumina/mullite interfaces exhibited no significant degradation following irradiation. • Alterations in Al-O bonding within the transition layer may contribute to the preservation of interfacial strength after irradiation. Silicon carbide (SiC) ceramics hold great potential for use in nuclear-reactor components due to characteristics such as high-temperature strength and low activation. Despite their resistance against corrosion in harsh environments, they suffer elevated corrosion rates under particle irradiation. Thin anti-corrosion coatings, such as mullite bond layers and alumina top layers, are essential to enhance the irradiation stability of SiC. The objective of this study was to evaluate the irradiation stability of a double-layer coating developed to enhance the corrosion resistance of SiC in nuclear applications. The coating, which comprised a mullite bond layer and an alumina top layer, was applied to a SiC substrate using laser chemical vapor deposition. Irradiation experiments were conducted at 300 °C with 5.1-MeV Si ions up to 10 displacements per atom. To assess the interfacial strength, a novel testing method, called the double-notch shear compression testing method, was developed based on ASTM standards and was implemented using a nanoindenter. This approach enabled precise measurements of the mechanical integrity at the interfaces of the coating under irradiation. The results showed an increase in the interfacial strength at the SiC/mullite and alumina/mullite interfaces with irradiation. Microstructural analysis of the fracture surface through scanning electron microscopy–energy-dispersive X-ray spectroscopy revealed that cracks propagated within the mullite layer, indicating the presence of mullite on the fracture surface. Transmission electron microscopy (TEM) images indicated that a 2-µm-thick transition layer existed at the SiC/mullite interface but not at the alumina/mullite interface. The TEM–electron energy loss spectroscopy suggested that the Al-O bonding structures in the transition layer were changed from tetrahedral (AlO 4) to octahedral (AlO 6) through irradiation, and this structural transition may directly affect the strength. [ABSTRACT FROM AUTHOR]

4H silicon carbide (4H-SiC) wafers are widely used in high-power, high-temperature, and high-frequency electronics owing to their excellent physical and electrical properties. In the processing of 4H-SiC wafers, chemical-mechanical polishing (CMP) is commonly employed to realize atomic-scale smoothness, damage-free surface, and global planarization. The CMP process is the synergy of wet oxidation and mechanical grinding, whose efficiency significantly relies on the oxidation process. Therefore, understanding the wet oxidation mechanism of Si face and C face of 4H-SiC wafers is critical to high-efficiency double-side CMP. In this work, the anisotropic CMP performance of Si face and C face of 4H-SiC wafers are investigated. It has been found that the material removal rate of the C face is 2–3 times that of the Si face. The thicknesses of the transient oxide layer on the C face and Si face are 8.71 nm and 3.50 nm, respectively. X-ray photoelectron spectroscopy analysis reveals that the oxygen content on the C face is higher than that on the Si face after wet KMnO 4 oxidation. This indicates that the C face of 4H-SiC is easier to oxidize, which results in more oxides that that on the Si face of 4H-SiC. Our work shows that accelerating the oxidation of the Si face of 4H-SiC wafers during the simultaneous double-sided CMP process is crucial for the efficient polishing of 4H-SiC wafers. [ABSTRACT FROM AUTHOR]

• Graphitisation process via temperature and time dependence was investigated. • Four different annealing procedures have been applied to show the role of selected parameters. • The time parameter determines a sufficient amount of free carbon atoms for graphene formation. • Temperature influences the surface structure condition and uniformity of graphene on the surface. This work investigates the temperature and time as key parameters for graphene formation on the silicon carbide surface during the high thermal decomposition process. Measurements were performed using various experimental techniques under ultra-high vacuum conditions. The graphitisation process was divided into various stages, after which the surface chemical composition and atomic structures were analysed in detail. It has been shown that despite the known theory of graphitisation mechanism and initial condition for occurrence of this process, the application of different temperatures and heating times affect the quality and quantity of formed graphene layers. Applying a temperature too low or annealing the sample for a too short time led to an inefficient silicon sublimation process. On the other hand, too high temperature during flashing modifies the visibility of surface structures, which may be crucial for other investigations and potential applications of such systems. [Display omitted] [ABSTRACT FROM AUTHOR]

Epitaxial growth of graphene on silicon carbide (SiC) facilitates the direct application of graphene in the semiconductor field. During the graphene preparation process, hydrogen plays a crucial role in determining its morphology. Therefore, studying the influence of hydrogen on the graphene morphology on the SiC surface is of great significance. In this study, we present a direct epitaxial growth of graphene on the SiC(0001) surface under atmospheric pressure. Our focus extends beyond the growth process itself to investigate the important role of hydrogen in shaping the quality and morphology of both the substrate and the graphene. By showing the influence of hydrogen at various stages, our research aims to contribute insights that advance the seamless integration of graphene into the semiconductor field. • We explore the details of SiC substrate pretreatment, highlighting the transformative effect of hydrogen on achieving well-defined terraces. • We provide a detailed examination of the impact of hydrogen on the morphology of epitaxial graphene. • High-quality graphene films are obtained under easily implementable atmospheric pressure conditions. [ABSTRACT FROM AUTHOR]

Silicon carbide (SiC) ceramic membranes are promising components for the efficient treatment of various wastewaters in membrane-based techniques. However, the high preparation temperature and then the high production cost inhibits their large-scale application. Here, an ultra-low temperature sintering process was proposed to prepare SiC ultrafiltration membrane. When the ceramic membrane was heated at 600 °C in air, a selective layer comprised of α-SiC and β-SiC formed without the emergence of crystalline silica. The thickness of the membrane layers was determined by the solid content and viscosity of the slurry. Well-dispersed SiC grains and homogeneous-distributed pores formed in the selective layers when using 100 nm SiC powders. The water flux and emulsion flux were investigated to verify the permeability of the ceramic membrane. Thus, this work proposes an energy-saving process for the preparation of SiC UF membrane and achieves the preparation of SiC UF membrane at ultra-low temperature. [ABSTRACT FROM AUTHOR]

Most previously reported susceptors for microwave welding are in powder form. In this study, a thin-film susceptor was employed due to its uniform heating rate and ease of handling. Silicon carbide nanowhisker (SiCNW) were incorporated into a poly(methyl methacrylate) (PMMA) matrix to create a nanocomposite thin film, which served as the susceptor. The microwave welding process involved three straightforward steps: fabrication of the PMMA/SiCNW nanocomposite thin film, application of the nanocomposite film to the target area, and subsequent microwave heating. Upon cooling, a robust microwave-welded joint was formed. The mechanical properties and microstructure of the welded joints were characterized using single-lap shear tests, three-point bending tests, and scanning electron microscopy (SEM). Results demonstrated that the shear strength and elastic modulus of the welded joints were optimized with increased heating time and SiCNW filler loading. This optimization is attributed to the formation of a SiCNW-filled polypropylene (PP) nanocomposite layer of increasing thickness at the welded joint interface. However, the incorporation of SiCNW also constrained the mobility of the PP chains, reducing the joint's flexibility. Furthermore, the welded joint formed with the PMMA/SiCNW nanocomposite thin-film susceptor exhibited an 18.82% improvement in shear strength compared to joints formed with a powdered SiCNW susceptor. This study not only demonstrates the potential of PMMA/SiCNW nanocomposite thin films as efficient susceptors for microwave welding but also paves the way for developing high-performance polymer-based composite joints with improved mechanical properties for applications in the automotive, aerospace, and construction industries.&#xD., (Creative Commons Attribution license.)