SiC Content Research Articles

Tailoring mechanical properties of Mo-SiC composites through controlled phase formation during reactive spark plasma sintering

The present study investigates the sintering behavior of Mo-xSiC reactive composites (x= 10–40 vol%) using reactive spark plasma sintering (RSPS) at 1700°C for 5 min. The microstructure, phase formation, and mechanical properties of the fabricated composites were evaluated. X-ray diffraction (XRD) analysis reveals the formation of various compounds, including Mo2C, Mo3Si, and Mo4.8Si3C0.6, which increase in intensity with increasing SiC content. It was found that composites with 10 vol% and 15 vol% SiC still contained unreacted Mo phase, whereas larger amounts of SiC resulted in no remaining Mo. Conversely, unreacted SiC particles were detected in all composites. Field-emission scanning electron microscopy (FESEM) and energy-dispersive spectroscopy (EDS) analysis confirm the presence of multiple phases. The flexural strength of the composites exhibits complex relationships with SiC content, with Mo-10 vol% SiC and Mo-15 vol% SiC composites showing superior strength (585±32 MPa and 618±21 MPa) due to the presence of unreacted Mo phase. The strength decreased with increasing SiC content, likely due to the formation of brittle intermetallic phases. Hardness increased with SiC content, with a significant improvement in Mo-20 vol% SiC composite (12.88 ± 0.21 GPa), but decreased thereafter. Fracture toughness followed a different trend, decreasing with increasing SiC content due to the elimination of ductile Mo phase and the formation of brittle phases. Therefore Mo-10 vol% SiC and Mo-15 vol% SiC composites exhibited the highest fracture toughness values of 8.34±0.68 MPa.m1/2 and 7.99±0.37 MPa.m1/2, respectively.

Influence of SiC content on the properties of Al/SiC composites produced by powder metallurgical route

Influence of SiC content on the properties of Al/SiC composites produced by powder metallurgical route

Effect of SiC content on the process and properties of PDMS/SiC composites by direct ink writing

Direct ink writing (DIW) has demonstrated great potential due to its convenience and effectiveness in the manufacturing of soft wearable devices. However, commonly used pure elastomer inks exhibit poor preservation characteristics and their thermal conductive properties require improvement. Considering this, a novel composite SiC ceramic ink with added polydimethylsiloxane (PDMS) was developed in this work. Subsequently, the impact of different SiC nanoparticle contents on the rheological, thermal, tensile, and tribological properties of the PDMS/SiC composites were investigated. The results showed that adding more SiC improved the viscosity of the samples, resulting in notable shear thinning behavior; this property proved to be conducive to the printing process. By printing the materials in the longitudinal and transverse directions, pure PDMS showed anisotropic tensile properties, while SiC addition resulted in isotropic properties. PDMS with an addition of 15 wt% SiC showed the greatest elongation at break (up to 120 %), and the samples exhibited better thermal conductivity with greater amounts of added SiC. Adding 5 wt% and 10 wt% SiC to PDMS reduces the coefficient of friction (COF), while 15 wt% SiC content results in the same COF as pure PDMS. These findings proved that PDMS/SiC could be a suitable printing material for future development, such as in the soft wearable electrics field of DIW.

Effect of SiC addition on the microstructure and properties of Ti6Al4V by selective laser melting

The fine crystalline behavior of SiC/Ti6Al4V is revealed in this study. Titanium matrix composites (TMCs) with different types, amounts, and morphologies of second phases were prepared in situ by adding different contents of SiC. The grain refinement mechanism of multi-phase synergistic was analyzed, and the synergistic contribution of the in-situ second phases (TiC, Ti5Si3, and Ti3Si) as well as the fine grain organization to the strengthening of the materials was quantitatively evaluated. The results show that the quasi-continuous network structure formed by the in situ TiC and Ti5Si3 phases inhibits grain growth and completes the equiaxed transformation of β-grains. Meanwhile, the TiC phase provides a large number of nucleation sites for the α-Ti phase, which promotes the nucleation of the matrix phase. Finally, the aspect ratio of the α phase was reduced from 5.8 to 3.1, while the β grain size was refined from 20.0 to 1.7 µm. The matrix hardness (6.3 GPa) and compressive yield strength (1692 MPa) of TMC were increased by 37 % and 67.4 % respectively compared with Ti6Al4V. Fine grain strengthening accounted for 71.2 % of the total strengthening increase. The load-bearing strengthening caused by TiC, Ti5Si3 and Ti3Si accounted for 6.0 %, 11.6 % and 3.0 % of the total strengthening increase, respectively.

Static and dynamic mechanical properties of aluminum nitride-silicon carbide whisker composites

AlN composites reinforced with SiC whiskers and Y2O3 sintering aids were fabricated using the hot-pressing technique to investigate static and dynamic mechanical properties. Microstructure analysis revealed that increasing SiC whisker content yielded grain refinement and decreasing relative density. The Vickers hardness increased from 10.29 to 14.47 GPa, while the fracture toughness improved from 3.03 to 4.39 MPa·m1/2 with 30 wt% SiC whiskers. A numerical approach for evaluating the dynamic modulus and loss factor is presented utilizing the wave propagation characteristics. The dynamic properties showed decreasing dynamic modulus and increasing loss factor with higher SiC content, attributed to increased porosity and interphase boundaries. Thermal conductivity, however, decreased from 139.53 to 49.95 W/m·K as SiC whisker content increased, primarily due to enhanced phonon scattering at grain and interphase boundaries. These findings suggest that AlN-SiCw composites are promising candidates for heat dissipation ceramic substrates, which offer superior mechanical strength and reliable thermal management.

Long‐term conservation tillage practices affect total carbon and contribute to the formation of soil aggregates in the semi‐arid North China Plain

AbstractThe soil aggregates characteristics and organic carbon (SOC) distribution under various tillage practices have been widely studied, but the changes in inorganic carbon (SIC) and their effect on soil aggregate formation are not clear. This study evaluated how long‐term tillage affects total carbon (both organic and inorganic) and contributes to forming aggregates in a fluvo‐aquic soil derived from limestone alluvial fans in the North China Plain. The four tillage practices that were used in a maize (Zea mays)/wheat (Triticum aestivum) double‐cropping system were moldboard plough without residues (CK), moldboard plough with residue retention (CT), rotary tillage with residue retention (RT) and no tillage with residue retention (NT). CT treatment, compared with NT treatment, decreased the SIC concentration at 0–300 mm and SOC concentration at 0–50 mm but increased the SOC concentration at 100–300 mm. Thus, there were no differences in the total carbon storage in the 0–300 mm layer because of the changes in SOC and SIC concentrations among four tillage practices. NT and RT practices increased the large macro‐aggregates (LM>2mm) and the mean weight diameter (MWD) only within the 0–50 mm layer, while the CT practice increased the LM>2mm and the MWD within the 100–250 mm layer. Correlation analysis revealed a significant link between LM>2mm and SOC, while small macroaggregates (SM0.25–2mm) were closely correlated with SIC. SOC and SIC had a relay cementation effect on the formation of large aggregates under long‐term tillage, and therefore, the effects of these two types of carbon should be comprehensively considered in the study of carbon sequestration and aggregate formation in calcareous soil.

Preparation and tribological performance of Ni-SiC composite coating on 304 stainless steel through brush plating

The low hardness of 304 stainless steels makes them susceptible to wear, which increasing the probability of workpiece failure during actual use. In this study, a Ni-SiC composite coating was successfully prepared on 304 stainless steel using brush plating equipment, effectively enhancing the material's surface wear resistance. By characterizing the microstructure and properties of the composite plating layer, we determined the optimal process parameters for brushing Ni-SiC wear-resistant plating and revealed the wear mechanism of this protective layer. When the parameters for preparing the composite plating coating were adjusted to a voltage of 10 V, a relative motion rate of 8 m/min, a plating solution temperature of 50 °C and a SiC concentration of 15 g/L, the resulting wear-resistant plating coating exhibited an impressive microhardness value of 457 HV0.1 and a friction coefficient of 0.46. It was observed that the fatigue wear mechanism dominated in Ni-SiC composite coatings with a solution SiC concentration below 5 g/L, while oxidative and abrasive wear mechanisms were dominant in Ni-SiC composite coatings with solution SiC concentrations exceeding 10 g/L.

Micromechanical properties of reaction-bonded silicon carbide using atomic force microscopy and nanoindentation

Reaction-bonded silicon carbide (RB-SiC) ceramics have been produced using advanced technology for the production of space mirrors. Changing the volume content of SiC (from 78 to 93 %) in the ceramic's composition allows for improved the mechanical properties, which is achieved by a combination of the SiC and Si phases properties. In this work, a thorough study of the structure and micromechanical properties of individual SiC and Si phases for RB-SiC ceramics (with a SiC content of 78–93 vol%) was carried out at the micro- and nanolevel using atomic force microscopy and nanoindentation. The studies have shown the crack resistance limit each phase (an important factor for RB-SiC space mirrors) under mechanical loads, after which microcracks appear (sources of further degradation and destruction). The surface morphology, deformation area and crack propagation in each phase after exposure to mechanical load during indentation were studied using atomic force microscopy. Nanomechanical mapping of elastic modulus and microhardness on the surface, analysis of boundaries between phases (SiC and Si), assessment of mutual influence of phases and determination of micromechanical properties were carried out using the nanoindentation method. The fracture toughness KIC was determined using an improved indentation method with visualization of the deformation areas using atomic force microscopy. The highest values of microhardness H, elastic modulus E and fracture toughness KIC on the SiC and Si phases were obtained on a ceramic sample with 93 vol % SiC: for the SiC phase – E=486 GPa, H=35.6 GPa, KIC=5.03 MPa m1/2, for the Si phase – E=205 GPa, H=12.2 GPa, KIC=2.73 MPa m1/2. This study demonstrated the efficiency and possibility of using the atomic force microscopy and nanoindentation to determine the micromechanical properties of ceramics at the micro- and nanolevel.

Effect of SiC Contents on Wear Resistance Performance of Electro-Codeposited Ni-SiC Composite Coatings

This paper focuses on the wear resistance performance of Ni-SiC composite coatings with various contents of SiC particles. The coatings were characterized via a scanning electron microscope (SEM), X-ray diffractometer (XRD), and transmission electron microscopy (TEM), and the wear behaviors of different coatings were tested. The results show that SiC particle incorporation results in a nanocrystalline metal matrix and nanotwins in nickel nanograins. The microhardness and wear resistance Ni-SiC composite coatings increased with the increasing SiC content. Microhardness was improved due to the grain-refinement strengthening effect and the presence of a nanotwin structure. The dominant wear mechanism was described in two stages: the first stage involves the interaction of SiC particles/the counter ball, and the second stage involves the formation of the oxide film its breaking up into wear debris. A higher SiC content increased the duration of the first stage and slowed down the rate of breaking up into debris, thereby decreasing the wear rate.

Research on the Corrosion Resistance of Electrodeposited Ni-SiC Composites Constructed for Steel Storage Tank Application.

In this paper, the effects of the SiC phase incorporated in Ni substrate deposits on storage tank steel during electrodeposition at different current densities are explored. The microstructure, phase content, and corrosion resistance of the resulting Ni-SiC composites were investigated by scanning electron microscopy (SEM) matched with energy disperse spectroscopy (EDS), X-ray diffraction (XRD), and an electrochemical workstation, respectively. SEM micrographs and EDS results show that at 2.5 A/dm2, the composites presented a smooth and compact structure with high SiC content, while at 1.8 or 3.2 A/dm2, it became uneven and loose in structure with low SiC content. XRD patterns showed that the nickel grain size of composites firstly increased and then decreased with the growth of the current density. Notably, the Ni-SiC composite produced at 2.5 A/dm2 possessed a higher corrosion potential (-0.507 V) and lower corrosion current density (2.439 μA/cm2), illustrating that its excellent anti-corrosion ability was superior than that of other two composites. Hence, SiC co-deposited at 2.5 A/dm2 conducted as a protective barrier and inhibited the corrosion rate against a corrosion medium of Cl- and SO42- ions. In addition, the corrosion relationship illustrated that the SiC content of Ni-SiC composite firstly increased and then decreased with the growth of the current density, while the corrosion weight loss of Ni-SiC composites firstly decreased and then increased.

Enhanced microstructures, mechanical properties, and machinability of high performance ADC12/SiC composites fabricated through the integration of a master pellet feeding approach and ultrasonication-assisted stir casting

Integrating ceramic particles into aluminum matrices poses significant challenges due to their limited wettability and high specific volume ratio. This research focused on developing ADC12/SiC aluminum composites with varying SiC concentrations (1.5, 2.5, and 3.5 wt%) through an innovative fabrication process. Initially, ADC12/SiC master pellets containing a high concentration of homogenously dispersed 1-μm SiC particles were produced. Subsequently, these master pellets were introduced into the molten ADC12 alloy, followed by the dispersion of SiC particles via stir casting assisted by ultrasonication. The study assessed the impact of SiC weight fractions on the microstructures, mechanical properties, and machinability of the fabricated composites. The results revealed significant microstructural improvements and a more even distribution of SiC reinforcement inside the ADC12 matrix after the application of this innovative processing method. Increased SiC concentration led to notable refinement of α-aluminum grains and eutectic Si, as well as a more uniform dispersion of intermetallic phases. Additionally, a substantial increase in tensile properties and hardness was observed with the increment of SiC content. Particularly, the ADC12/3.5 wt%SiC composite exhibited a 46.73% increase in hardness and notable enhancements in yield strength, ultimate tensile strength, and elongation, denoted as 201.7 MPa, 241.1 MPa, and 3.40%, respectively, as compared with those of the unreinforced ADC12 alloy. Moreover, the ADC12/SiC composites demonstrated reduced surface roughness compared to the unmodified ADC12 alloy, indicative of a superior surface finish. With the addition of a high SiC content, the chip morphology was observed to change from continuous to discontinuous following a turning operation.

Preparation and tribocorrosion behavior of electrodeposited Ni–W/ SiC composite coatings

Ni-W composite coatings that are applied using electrodeposition exhibit excellent mechanical strength, corrosion resistance and wear resistance and are a substitute for hard chrome because they involve fewer environmental hazards than regular chromium plating processes. This study determines the effect of process parameters, such as current density (5, 10 and 15 A/dm2) and SiC concentration (0.5, 1.0 and 1.5 g/L), on the chemical composition, structure, mechanical properties and corrosion resistance of electrodeposited Ni-W/SiC composite coatings and determines the interaction between the mechanical behavior and the electrochemical reactions that occur during corrosion and friction. The experimental results show that there are no cracks on the surface of the coating and that the surface roughness increases as current density increases. As the content of W and SiC particles in the composite coating increases, the hardness and corrosion resistance of the coating increase because of solid solution strengthening and nano-ceramic particle dispersion strengthening.In order to verify the protective performance of the coating in complex environments, a ball-on-disk abrasion tester and a potentiostat are used to determine the tribocorrosion behavior of the Ni-W/SiC composite coating against the sliding of the Al2O3 counter-body. In 3.5 wt%NaCl solution and at +600 mV, the corrosion and wear characteristics of composite coatings that are produce using different process parameters are determined. Analysis of the synergistic effects of corrosion and friction shows that the wear component (△Wwear) is 3–5 times greater than the corrosion component (△Wcorr), which is the main cause of coating damage. The greater the hardness of the coating, the less mass is lost for the wear component (△Wwear). The results show that the operating parameters for producing ideal Ni-W/SiC composite coatings are a SiC particle concentration 1.0 g/L and a current density of 10A/dm2. These settings give the best wear resistance in corrosive environments.

Phase formation, microstructure and mechanical properties of TaB2–SiC composites synthesized by reaction hot pressing: Effects of SiC contents and oxygen impurity

TaB2–SiC composites with 0–20 wt% SiC contents were prepared by reaction hot pressing using Ta, B and SiC powders as starting materials. Densification, constituent phases, microstructure and mechanical properties, namely Vickers hardness, fracture toughness and flexure strength, were evaluated by means of inspection of sintering shrinkage, density measurement, XRD, SEM, TEM, HRTEM, EDS, SAED, indentation and three-point bending tests. Phase formation, including dominant (TaB2, SiC) and minor (TaC, glassy SiO2) phases, was checked by thermodynamic assessment relevant with Ta2O5 and B2O3 impurities introduced into the reaction system by the starting powders. The results showed that mixtures of Ta, B and SiC powders would initiate self-propagating combustion synthesis (SPCS) at about 900 °C; a transient hold at 800 °C for 1 h could suppress this reaction. Volatilization of B2O3 impurity in association with local high temperature due to SPCS helped reduce the TaC and glassy SiO2 minor phase formation. TaB2–SiC composites could reach 99 % relative densities with 3 wt% SiC addition and above. Compositions with <7.5 wt% SiC additions showed uniform dispersion of SiC particles at multi-TaB2 grain junctions while compositions with higher SiC content revealed SiC segregation. Bending strength of 503 MPa and fracture toughness of 6.69 MPa⋅m1/2 could be reached with 7.5–20 wt% SiC addition.

Gradient high-Content SiC/Al composites via innovative filtration-Extrusion

High-content SiC/Al materials have great potential for thermal management applications in electronic devices owing to their excellent thermal performances. This paper introduces a novel approach to prepare gradient high-content SiC/Al composites using filtration-extrusion technology. The results reveal that the extrusion pressure increases with the filtration-extrusion ratio. In the initial stage, SiC particles are squeezed into the die separation holes, but the distribution range is limited. As the extrusion pressure sharply increases, the distribution range of SiC particles in the separation holes significantly expands, leading to a larger deviation between the actual SiC content and the designed content. A lower extrusion temperature, larger separation hole-to-mold area ratio and higher initial SiC content all contribute to a larger discrepancy. This study provides valuable insights into the filtration-extrusion process, offering a foundation for optimizing the production of high-content SiC/Al composites and enhancing their thermal management applications.

Biomimetic structure-driven high strength and toughness in continuous SiC skeleton-reinforced graphite composites

Graphite-matrix structural composites with excellent mechanical properties and long-term reliability are ungently required in aerospace and nuclear industries. However, the enhancement of graphite-matrix composites by mainstream surface coating techniques or second-phase particle reinforcement is rather limited. Inspired by the structural-functional feature of plant cells, silicon carbide (SiC, cytoderm) coated mesocarbon microbeads (MCMB, cytoplasm) powders were prepared by combustion synthesis (CS), which were then densified via spark plasma sintering (SPS) to obtain the biomimetic cellular-structured SiC-reinforced MCMB (M@SiC) composites. The in-situ formed SiC ‘cytoderm’ ensures good interfacial bonding and contributed to the densification of the composites. Additionally, the continuous SiC skeleton and cellular-structured configuration improved the mechanical properties of M@SiC composites. Owing to the complex crack deflection, branching and bridging effects at the MCMB/SiC interfaces and graphite nanoflakes inside MCMB, the biomimetic M@SiC composite with SiC content of 47 vol% exhibited strengthening and toughening, with flexural strength and fracture toughness of 245 MPa and 3.82 MPa m1/2, respectively. The developed biomimetic graphite-matrix composites with excellent mechanical properties are expected to be applied in reusable spacecrafts and high-temperature gas-cooled reactors.

Hot extrusion of SiCp/Al-Cu composites: optimizing mechanical properties through microstructural control

The solid-state processing and utilization of light-metal-based composites align with green policies by reducing the weight of components and employing lower processing temperatures compared to traditional metallurgical methods. This study explores the incorporation of SiC particles at concentrations of 5 and 10 wt.% into an Al4Cu matrix through powder mixing, compaction at 235 MPa, hot extrusion, and sintering at 600 °C in a nitrogen atmosphere. The resulting microstructure, hardness, compressive strength, and flexural strength of the composites were evaluated. During extrusion, the composite underwent plastic deformation, leading to cracking and fragmentation of the SiC particles within the matrix. Therefore, evenly distributed reinforcing particles with a diameter much smaller than the originally introduced ceramic particles were observed. Recrystallization also occurred, with Al2Cu precipitates forming on grain boundaries and nanosized Al2O3 oxides observed in porous areas and at matrix-reinforcement interphase boundaries. The composite containing 5 wt.% SiC exhibited the highest compressive strength of 305 MPa, while the composite with 10 wt.% SiC achieved the highest flexural strength of 889 MPa. However, non-deformable SiC particles crack before reaching maximum strength due to stress concentration at their sharp edges, initiating microcracks in the matrix. Microstructural analysis further revealed that SiC particles tend to crack during hot extrusion, reducing their effectiveness in stress transfer. The hardness remained constant at 78 HV1, irrespective of SiC content. These findings demonstrate that the addition of SiC particles significantly enhances the mechanical properties of Al4Cu composites, making them promising materials for lightweight and high-strength applications.

Distinct features of topsoil carbon fractions across urban forests in eastern China

AbstractRapid urbanization has increased the areas of urban forests that store considerable soil carbon (C). Different soil C fractions may show distinctive contents and spatial patterns in view of their contrasting sensitivities to various drivers. However, current studies on soil C fractions are mostly limited to natural ecosystems and little is known about the large‐scale patterns and drivers of soil C fractions in urban forests. Based on a field survey of urban forests across a north–south transect in eastern China, we analysed the spatial variations and main drivers of topsoil (surface layer, 0–10 cm; subsurface layer, 10–20 cm) C fractions (i.e., soil organic C, SOC; soil inorganic C, SIC; particulate organic C, POC; mineral‐associated organic C, MAOC). Our results showed that topsoil contents of POC, MAOC and SOC changed non‐linearly with latitude, with lowest values occurring in the cities in the warm temperate region. In contrast, SIC content showed the highest values in the warm temperate region. POC instead of MAOC was found to be a major fraction of SOC in urban forests. The spatial variation in topsoil POC content was mainly explained by mean annual temperature, soil clay and silt content, and park age. The spatial variation in MAOC content was mainly explained by soil clay and silt content, mean annual precipitation, mean annual temperature and park age. In contrast, the spatial variation in SIC content was mainly explained by mean annual precipitation and soil pH. These findings demonstrate distinct features of different soil C fractions in urban forests and provide useful implications for urban soil carbon management.

Influence of ultrasonic power on microstructure and performance of electroless deposited Ni-W-SiC nanocoatings

This study reports the deposition of Ni-W-SiC nanocoatings on the 45-steel using the ultrasound-assisted electroless deposition (UELD) technique. The hardness and corrosion resistance of the nanocoatings were evaluated through microhardness tests and electrochemical analyses. The surface, cross-section, phase composition, and abrasion morphologies of the coatings were studied using scanning electron microscopy and X-ray diffraction. The findings indicated that the Ni-W-SiC coating obtained at 200 W showed a compact, fine, and flat microstructure with a porosity of only 0.03 %. As the ultrasonic power during the UELD process increased from 0 W to 200 W, the SiC content in the coating rose from 2.77 to 4.16 wt% The maximum bonding force of the coating synthesized without ultrasound was approximately 89.8 N. However, the bonding force of the coatings significantly decreased with increasing ultrasonic power. The coating’s thickness also increased, from 11.09 μm at 0 W to 14.97 μm at 300 W. At 200 W ultrasonic power, the diffraction peaks of the coating were both the lowest and broadest among all the coatings. Further, the coating achieved the highest microhardness value of 676 HV. At 200 W ultrasonic power, the coating's corrosion current density was 1.63×10−7 A/cm2, which is only one-twelfth that of 45 steel, demonstrating exceptional corrosion resistance. The electrochemical impedance spectroscopy (EIS) testings indicated that an excellent corrosion resistance of Ni-W-SiC coating was deposited by using a 200 W ultrasonic power. This study provides a technical support for the preparation of nickel-based composite coatings.

Ablation and mechanical behavior of reusable Cf/SiC-ZrC with a gradient-structured matrix produced by reactive melt infiltration

Cf/SiC-ZrC renowned for its outstanding performance as a thermal protectant, has gaining widespread recognition. Recent research on this system has emphasized the development of a cost-effective and reusable version with increased thickness for extended use in thick-walled thermal structural components. Ablation resistance, high strength retention, and high thermal conductivity are crucial for successful aircraft reentry. In this study, a low-cost reactive melt infiltration (RMI) method is developed for preparing dense and high-performance large-thickness Cf/SiC-ZrC (L-Cf/SiC-ZrC) with a gradient-structured matrix. The use of a fine weave-pierced fabric preform structure enhances both the structural integrity and thermal conductivity of Cf/SiC-ZrC in the thickness direction. Simultaneously, the gradient-structured matrix, with appropriate contents of surficial ZrC and SiC exhibits erosion resistance, where the internal core with a high SiC content ensures remarkable strength retention. This unique matrix-structure design is achieved by integrating porous C with a single-stage pore structure and a high degree of graphitization degree, and a Si-Zr alloy with a unique composition. The 20 mm thick Cf/SiC-ZrC obtained via RMI has a density of 2.79 g/cm3 with an open porosity of 5.65 % and flexural strength of 224.3 ± 5.4 MPa. Under a heat flux of 4.186 MW/m2, Cf/SiC-ZrC exhibits an ablation rate of −0.004 mm/s after 60 s, demonstrating its resilience against ablation damage. Moreover, the post-ablation strength (166.0 ± 4.4 MPa) exceeds that of reported Cf/SiC-ZrC congeners, highlighting the robust load-bearing capability.

Preparation and microwave absorption performance of SiC aerogel via sol-gel and carbonization reduction process

SiC aerogel presents several advantageous features like lightweight and high temperature resistance when applied as microwave absorbing material. In this paper, SiC aerogel was prepared eventually followed by the sol-gel and carbonization reduction process. The results showed that the effective electromagnetic microwave absorption capacity of SiC aerogel was highly increased after being pyrolyzed at 1500 °C, which presented a minimum reflection loss value of −57.80 dB at 3.10 mm and 9.86 GHz. Besides, the electromagnetic parameters of SiC aerogel with different paraffin ratios were discussed as well as the varying electromagnetic microwave absorption performances. The minimum reflection loss value first rose then fell as the SiC/paraffin ratio increased, which demonstrated the importance of SiC content. This study establishes the theoretical foundation for the subsequent functional application of SiC aerogel.