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This study investigates the mechanical properties and erosion resistance of high temperature–pressure carbon‐epoxy novolac insulation reinforced with ZrB2/SiC particles. For this reason, at first, five samples were fabricated using the hot press, which included resin epoxy novolac EPN1180 base without reinforcement and four samples containing resin with 20:80, 30:70, 40:60, and 50:50 of SiC: ZrB2 particles respectively. After manufacturing of the samples, the mechanical properties were evaluated through bending and tensile testing, followed by erosion resistance properties by the use of oxyacetylene flame erosion tests. Chemical composition and surface morphology analysis of the composites were conducted using energy‐dispersive spectroscopy, scanning electron microscopy, and x‐ray diffraction analysis. Results indicate that the addition of ceramic particles enhances both mechanical properties and erosion resistance of the composite. The pure resin sample exhibited the highest weight loss and thickness reduction, while the sample containing 40% SiC and 60% ZrB2 demonstrated the least weight loss and thickness reduction about 55% and 83% respectively compared to pure sample. Additionally, the sample with 30% SiC and 70% ZrB2 had the lowest backside temperature. Furthermore, the sample with 20% SiC and 80% ZrB2 exhibited the highest mechanical properties, with a tensile strength of 422.5 MPa and flexural strength of 587.11 MPa. Morphological analysis revealed the presence of phases such as SiO2, ZrO2, and ZrSiO4 attributable to the ZrB2/SiC particles, contributing to the enhancement of erosion resistance. Highlights: Examines volume ratios of ZrB2/SiC.Discovers the best particle ratio (20%SiC, 80%ZrB2) for mechanical properties.Identifies the best particle ratio (30% SiC, 70% ZrB2) for erosion resistance.Reveals key phases enhancing erosion resistance with advanced analysis methods.Linear and mass ablation rate improved by 83% and 55% (best formation). [ABSTRACT FROM AUTHOR]

Additive manufacturing technology is being developed for manufacturing SiC ceramic parts with designed shape and microstructure. In this study, direct ink writing (DIW) was adopted to print SiC ceramic parts. To avoid incorporating volatile organic solvents or water, a SiC ceramic precursor liquid polycarbosilane (LPCS) was used as the binder of SiC powder and the rheological adjustment additive. The content of LPCS with the content and diameter of SiC powder were optimized to improve the fluidity of slurry, increase its ceramic yield and reduce its shrinkage during pyrolysis. According to the results of rheological analysis and shrinkage during pyrolysis, 78 wt% SiC powders composed of 40 nm SiC powder and 5 μm SiC powder in a ratio of 1:6 was appropriate. For achieving rapid solidification rate of the slurry at low temperature, a free‐radical initiator which can trigger the crosslinking of allyl group on LPCS was incorporated. According to the results of rheology, DSC and FT-IR, the preferred platform temperature for fast curing of DIW slurry was 150 °C. As the slurry accumulated layer by layer on heating platform, the cured green bodies were successfully prepared. After pyrolysis to 1200 °C, SiC ceramic parts were obtained with only 4.43 % linear shrinkage associated with the precursor-to-ceramic conversion. Because the shrinkage was limited, no obvious deformation or crack was found. [ABSTRACT FROM AUTHOR]

Yttrium-containing ceramics exhibit excellent resistance to water-oxygen corrosion, making them an attractive choice as the modified matrix for SiC f /SiC composites. However, the oxidation products of yttrium-containing ceramics are complex and vary widely in performance. In this study, YSOC ceramics, which are composed of yttrium silicate, SiO 2 , and SiC, were prepared using Y 2 O 3 , SiO 2 , SiC, and Li 2 CO 3. This research investigated the effects of high temperatures, air oxidation, and water-oxygen corrosion on the phase compositions of YSOC ceramics. The influence of environmental factors on the synthesis and decomposition of yttrium silicate was analyzed. Moreover, the study explored the compatibility of different oxidation products with SiC. The results suggest that Y 2 SiO 5 and Y 2 Si 2 O 7 are formed through the low eutectic of SiO 2 , Y 2 O 3 , and Li 2 CO 3. The high SiO 2 content likely contributes to the relatively low formation temperature of Y 2 Si 2 O 7. In the oxidizing environment, Y 2 SiO 5 reacts with SiO 2 to produce Y 2 Si 2 O 7. Conversely, in the water vapor-containing atmosphere, Y 2 Si 2 O 7 undergoes hydrolysis to form Y 2 SiO 5. Y 2 Si 2 O 7 displays a reduced elastic modulus in comparison to SiC fibers and exhibits favorable physical and chemical compatibility with SiC fibers. However, the hydrolysis of Y 2 Si 2 O 7 may potentially affect the water-oxygen corrosion resistance of the ceramics. These findings will significantly advance research and enhance understanding of the water-oxygen corrosion behaviors of yttrium-containing matrix-modified composites. [ABSTRACT FROM AUTHOR]

Room‐temperature (RT) 2D van der Waals (vdW) ferromagnets hold immense promise for next‐generation spintronic devices for information storage and processing. To achieve high‐density energy‐efficient spintronic devices, it is essential to understand the local magnetic properties of RT 2D vdW magnets. In this work, noninvasive in situ stray field detection is realized in vdW‐layered ferromagnet Fe3GaTe2 using divacancy spins quantum sensor in silicon carbide (SiC) at RT. The structural features and magnetic properties of the Fe3GaTe2 are characterized utilizing X‐ray diffraction, scanning tsransmission electron microscopy, Raman spectrum, magnetization, and magneto‐transport measurements. Further detailed analysis of temperature‐ and magnetic field‐dependent optically detected magnetic resonances of the PL6 divacancy near the Fe3GaTe2 reveal that, the Curie temperature (Tc) of Fe3GaTe2 is ∼360 K, and the magnetization increases with external magnetic fields. Additionally, spin relaxometry technology is employed to probe the magnetic fluctuations of Fe3GaTe2, revealing a peak in the spin relaxation rate around the Tc. These experiments give insights into the intriguing local magnetic properties of 2D vdW RT ferromagnet Fe3GaTe2 and pave the way for the application of SiC quantum sensors in noninvasive in situ stray field detection of related 2D vdW magnets. [ABSTRACT FROM AUTHOR]

A novel α/β SiC-(Ti, Nb)B 2 toughened (Ti, Nb)C-based composites was fabricated by reactive hot pressing with TiC, NbB 2 and Si powders at 1500 °C and 1600 °C, respectively. The influence of NbB 2 , Si content, and sintering temperature on the microstructure and mechanical properties of the composite was investigated. The intermediate product NbC reacts with Si to form NbSi 2 and β-SiC phases. With addition of 10 mol% NbB 2 , a toughening phase α-SiC was formed. During the reaction process, insufficient diffusion of Nb atoms in TiC leads to the formation of a specific "core-shell" microstructure, which improves the flexural strength of the composite ceramics. The (Ti, Nb)C has a specific crystallographic orientation relationship with NbSi 2 and α-SiC. The high-density stacking faults and ordered structures in β-SiC crystals enhances its hardness. The rod-shaped α-SiC and plate-like (Ti, Nb)B 2 by in situ reactions effectively improve the fracture toughness of the composites. TiC-32 mol% Si-10 mol% NbB 2 (raw powder composition) sintered at 1600 °C has excellent comprehensive mechanical properties, with fracture toughness, flexural strength, and Vickers hardness of 5.45 MPa·m1/2, 665 MPa, and 22 GPa, respectively, which provide a new insight into the optimization strength and toughness of TiC-based composites. In addition, under high temperature oxidation of 1000∼1200 °C, the 30NB (54 mol% TiC-16 mol% Si-30 mol% NbB 2) sample has better high-temperature oxidation resistance than the 30ZB (54 mol% TiC-16 mol% Si-30 mol% ZrB 2) sample. [ABSTRACT FROM AUTHOR]

High-entropy carbides-SiC biphasic ceramics demonstrate outstanding mechanical and oxidation resistance properties. However, previous studies have predominantly focused on fabricating dense monolithic high-entropy carbides-SiC biphasic ceramics, with limited attention given to the production of high-purity, narrow particles size distribution high-entropy carbides-SiC biphasic ceramic powders. In this study, we successfully synthesized high-entropy carbides-SiC biphasic ceramic powders, specifically (Hf 0.25 Zr 0.25 Ta 0.25 Ti 0.25)C-SiC, utilizing the polymer-derived-ceramic (PDC) route employing transition metal alcohol solution and methyltrimethoxysilane. The resultant powders exhibited an average particle size of ∼15 μm, with a narrow particle size distribution. Furthermore, variations in the heat treatment temperature demonstrated minimal impact on the particle size, while maintain compositional homogenous from nanoscale to microscale, and exhibiting low oxygen content less than 1.01 %. The introduction of the SiC phase also enhances the dynamic oxidation resistance of the high-entropy carbides. This pioneering work will not only provide a novel approach for obtaining other high-entropy carbides and SiC biphasic ceramic powder but also offers prospects for large-scale fabrication in industrial. [ABSTRACT FROM AUTHOR]

SiC particles coated with Ti-Si-C layer were prepared by the molten salt synthesis method using NaCl-KCl eutectic mixture as the reaction medium and Ti metal powder as the Ti source. The synthesis was conducted under static argon atmosphere at 900 °C for 1–3 h. The post-synthesis treatment included dissolution of salts in hot water, followed by ultrasonic dispersion and sedimentation procedures. The thickness of the Ti-Si-C layer varied from 0.1 to 0.9 μm as the ratio of Ti to SiC components in the starting mixture changed from 0.05 to 0.4. The layer contained mainly nanocrystalline Ti 5 Si 3 , minor phases were TiC and Ti 3 SiC 2. The as-prepared powders were hot pressed under 30 MPa at 1700 °C. The densification behavior of the samples during hot pressing as well as changes both in phase composition and in microstructure were studied. The flexural strength of the hot-pressed samples increased with an increase in the Ti:SiC molar ratio, giving the value as high as 213 ± 20 MPa for the sample with Ti/SiC = 0.4. [ABSTRACT FROM AUTHOR]

This study aims to extend the work-life of diamond-cutting segments and to economize the operating cost of diamond-cutting tools. In order to achieve this object, bronze matrix sandwich segments reinforced with SiC and B 4 C were produced utilizing the hot pressing technique. In the term of the cutting segments, it is favorable that the outer layers are wear-resistant and the middle layer is tough. SEM and XRD analysis were used to determine the microstructural properties. Mechanical properties were evaluated by conducting hardness, wear, cutting performance, and three-point bending tests. The cutting performance of the segments was determined by turning andesite marble. SEM examinations showed that SiC and B 4 C grains were homogeneously distributed in the bronze matrix. The highest hardness value was 113.9 HB in the B 4 C reinforced sandwich segment. The reciprocating wear test findings indicated that the matrix exhibited the lowest wear rate in the B 4 C reinforced sandwich composite segment, followed by the hybrid sandwich composite segment. The lowest amount of cutting loss after turning andesite stone was achieved in the SiC, and B 4 C reinforced hybrid sandwich composite segment. The cutting performance of the hybrid sandwich composite segment increased by 46.15 % compared to the conventional segment without additives. The highest value of the transverse rupture strength of the specimens was 380 MPa for the B 4 C reinforced sandwich composite segment and 352 MPa for the hybrid sandwich composite segment. Considering all the tests and analyses, the hybrid sandwich composite segment sample may be the most suitable for diamond-cutting tools. [ABSTRACT FROM AUTHOR]

AbstractThe present investigation focuses on the synthesis of mono (AA5052/SiC and AA5052/graphene) and hybrid (AA5052/SiC/graphene) surface composites using friction stir processing (FSP). This work examines the synergistic effect of SiC and graphene on the fabricated surface composites. Macro/microstructure, microhardness, and wear test analysis were done on these samples, and the results were compared with the base material AA5052-H32. The microstructure analysis showed that the distribution of reinforcement particles in the aluminum matrix is made more uniform by adding hard SiC with graphene nanoparticles, which can reduce the occurrence of particle clustering and agglomeration. As a result, the smallest grain size of 11.2 µm and the highest microhardness obtained was 84.1 HV obtained in hybrid surface composites. Consequently, the hybrid surface composites obtained more improved wear properties than mono surface composites. Thus, the hybrid surface composites achieved the lowest average friction coefficient of 0.304. [ABSTRACT FROM AUTHOR]

In recent years, SiC aerogels have attracted considerable research interest owing to their excellent high-temperature resistance. It is crucial to research and improve the thermal stability of SiC aerogels under long and multiple heat treatments. Herein, we develop a series of monolithic SiC aerogels with a density of 0.23–0.28 g cm−3, low-thermal linear shrinkage of 21%–27 %, and high compressive strength of 0.38–0.60 MPa by designing a novel core–net structure. The resulting aerogels exhibit excellent thermal insulation thermostability and high-temperature reusability. Thermal conductivities of 0.0455–0.0678 W K−1 m−1 and 0.0934–0.1313 W K−1 m−1 were achieved at 40 °C and 900 °C, respectively. Following three consecutive heat treatments using a butane spray gun for 2000 s, the macromorphology exhibited no change, and the backside temperature was 230 °C. The results demonstrate an effective solution to reuse aerogels as long-lasting high-temperature insulation materials. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive exploration of advanced beamforming techniques tailored for millimeter-wave (mm-Wave) communication systems. In response to the burgeoning demand for higher data rates, coupled with the constraints of power consumption and hardware complexity, this study focuses on developing a hybrid beamforming framework optimized for downlink scenarios, specifically targeting groups of users based on the approximate symmetry of their channels. The primary innovation of this research lies in leveraging the symmetry of channels among near users to develop a group-based successive interference cancellation (SIC) algorithm. Unlike traditional approaches that address interference on a per-user basis, this algorithm utilizes channel symmetry within clusters of users to reduce computational complexity and improve the efficiency of SIC. By grouping users with symmetrical channel characteristics, the algorithm simplifies the interference management process while maintaining system performance. The proposed system demonstrates notable advantages over existing non-linear algorithms through extensive simulations and performance evaluations, particularly in terms of spectral efficiency and computational complexity. In this study, we further emphasize the importance of balancing spectral efficiency improvements with reduced computational demands, offering a nuanced trade-off that accommodates various operational requirements. The flexible optimization framework provided showcases the system's adaptability to diverse deployment scenarios and network configurations. [ABSTRACT FROM AUTHOR]

Statistical hypothesis testing, as formalized by 20th century statisticians and taught in college statistics courses, has been a cornerstone of 100 years of scientific progress. Nevertheless, the methodology is increasingly questioned in many scientific disciplines. We demonstrate in this paper how many of the worrisome aspects of statistical hypothesis testing can be ameliorated with concepts and methods from evidential analysis. The model family we treat is the familiar normal linear model with fixed effects, embracing multiple regression and analysis of variance, a warhorse of everyday science in labs and field stations. Questions about study design, the applicability of the null hypothesis, the effect size, error probabilities, evidence strength, and model misspecification become more naturally housed in an evidential setting. We provide a completely worked example featuring a two-way analysis of variance. [ABSTRACT FROM AUTHOR]

In this study, SiC quantum dots (SiC‐QD's) are studied, and some roundish SiC‐QD's with the incorporation of defects by removing a carbon or silicon atom are considered. Fourteen configurations are modeled in which the position of the silicon or carbon defect for each configuration is changed, considering that due to the chemical composition, it allows more Si atoms or more C atoms on the QD surface. All calculations are performed using the Density Functional Theory (DFT) methodology. The electronic exchange correlation is treated using the Generalized Gradient Approximation (GGA) with the Revised Perdew–Burke–Ernzerhof (RPBE) functional. The electronic energy levels of each configuration are calculated as well as the partial density of states to know the origin of the energy gap in each quantum dot. The final step is to analyze the energy formation to determine chemical stability. [ABSTRACT FROM AUTHOR]

A combination of fluorescent SiC (f‐SiC) and porous f‐SiC is a promising phosphor material for pure white light emission. Herein, the anodic oxidation condition is optimized to produce porous f‐SiC. Furthermore, a hybridly packaged white light emitting diode (LED) package composed of f‐SiC/porous f‐SiC stacks with a nitride‐based NUV‐LED as an excitation source is fabricated. A distinct pure white light emission and the peak luminous efficacy of 11.6 lm W−1 at a forward current of 10 mA in the NUV‐LED are observed. At the peak luminous efficacy, the estimated internal quantum efficiency of the f‐SiC/porous f‐SiC stacks is ≈80% as the package involved several types of optical and energy losses. [ABSTRACT FROM AUTHOR]

A method for improving the properties of the deposited metal in wire arc additive manufacturing of Al–Si alloy is proposed here, which introduces SiC ceramic particles into the side-axis wire feed. The effects of SiC ceramic particles on the macroscopic morphology, microstructure and mechanical properties, corrosion resistance, and wear resistance of deposited metals were studied. The results show that the introduction of SiC particles will not affect the surface-forming quality of the deposited metal; this is likely due to the stable droplet transfer and no splashing. The transverse and longitudinal tensile strengths are increased by 10.1 % and 11.3 %, respectively, while the corresponding elongations are increased by 33.1 % and 47.2 %, respectively. Further, the corrosion resistance and wear resistance of Al–Si alloy deposited metals containing SiC are improved. The (100) base surface has strong texture characteristics along the deposition direction X0, and the maximum polar density decreases to 13.63, which indicates that SiC promotes the transformation of columnar crystals to equiaxial crystals. The interface between SiC and Al is non-coherent, and the performance improvement lies in the enhanced dispersion distribution and load transfer of SiC. A ring structure was prepared using double-wire arc additive manufacturing technology, and the feasibility of side-axis wire feeding technology was verified. [ABSTRACT FROM AUTHOR]

Synthesis of porous ceramic materials based on fine SiC with sintering silicon oxide and magnesia binders at T = 800–1300 °C is considered. Special attention is paid to the influence of the shape and morphology of the initial powder particles on structural parameters and characteristics of porous ceramic materials. The SiC membranes sintered at 1000–1300 °C had average pore sizes of 0.5–1 μm, open porosity - up to 50 %, bending strength - up to 48.5 MPa and high water permeance - up to 7890 l⋅m−2⋅h−1⋅bar−1. The established filtration efficiency was ∼99 % in the case of screening out model particles of D 50 = 0.5 μm in size with maintaining stable permeance and physico-mechanical characteristics after multiple filtration-regeneration cycles. Comprehension of the initial powders morphology impact on the synthesized porous ceramics parameters makes it possible to forecast and ensure the preset structural, dimensional and physico-mechanical parameters of the materials under study properly. This work can be used for practical low-cost production of highly efficient SiC membranes for micro- and ultrafiltration processes, as well as base for catalysts. [ABSTRACT FROM AUTHOR]

A high‐entropy rare‐earth disilicate (Er0.25Y0.25Ho0.25Yb0.25)2Si2O7 (hereinafter referred to as (EYHY)2Si2O7) ceramic was synthesized by a heat treatment process combined with spark plasma sintering. According to the experimental results, (EYHY)2Si2O7 presents good phase stability and low thermal conductivity ([1.48–2.35] W∙m−1∙K−1) from room temperature to 1200°C. Its coefficient of thermal expansion is (3.89–5.32) × 10−6 K−1 from 200 to 1400°C, similar to SiC‐based materials ([4.5–5.5] × 10−6 K−1). Due to the multiple doping effects, (EYHY)2Si2O7 exhibits outstanding corrosion resistance performance in water‐vapor corrosion tests. Its weight loss is 1.79 mg/cm2 after corrosion at 1600°C for 30 h in the presence of 50% H2O‐50% O2, which is lower than the corresponding four single components Re2Si2O7 (Er2Si2O7, Y2Si2O7, Ho2Si2O7, and Yb2Si2O7) under the same conditions. Therefore, high‐entropy (EYHY)2Si2O7 ceramics are regarded as potential environmental barrier coatings materials for SiC ceramic matrix composites. [ABSTRACT FROM AUTHOR]

Silicon carbide (SiC) is widely used in various industrial fields for its excellent properties. Vat photopolymerization (VP) technology stands out in the fabrication of SiC ceramics due to its enhanced design flexibility and capability to produce intricate geometries. However, the excessive residual carbon content in VP technology directly affects the sintering performance of SiC ceramics, leading to cracking and deformation defects. To address this issue, we systematically studied the residual carbon content of SiC under different debinding atmospheres in forming by VP technology. We found that the debinding atmosphere can effectively control the residual carbon content in SiC ceramics. Residual carbon exists in samples with a lower degree of defect, promotes grain growth, reduces neck size, and results in flexural strength of 253.13 MPa after pressureless sintering. This research promotes the application of VP technology in SiC ceramics and opens up a new avenue for the development of high-performance SiC ceramics. [ABSTRACT FROM AUTHOR]

High flight speed of hypersonic vehicles will push thermal insulation composites to achieve balanced enhancement of high porosity with increasing load-bearing capability. Herein, hierarchically porous SiC(rGO) polymer-derived ceramics (PDCs) with lightweight, heat-insulating, anti-ablative and tough engineered merits, are designed from polycarbosilane-vinyltriethoxysilane-graphene oxide precursors by re-pyrolysis/graphite-assisted decarburization. Graphite pore-forming agents tightly coupled with SiO x C y /C free (rGO) by C-dangling bonds, can inhibit SiO x C y decomposition, increase ceramic network disorder and expedite concurrent removal of C free. SiO 2 generated from Si-dangling oxidation bonding, efficiently densifies framework to retain mechanical performances, and meanwhile creates more interfaces to enhance phonon scattering. Such structure similar to nodular cast iron confers low thermal conductivity (0.11 W·m-1·K-1), particularly, fully preserves good compressive strength (5.4 MPa) for SiC(rGO) 40%. Under both cyclic butane flame ablation (∼1300 °C) and long-term oxidation for 7200 s, self-healing effect of SiO 2 imbues products with good structural integrity, shedding light on the opportunity to apply any thermal protection system. [Display omitted] • Hierarchically porous SiC(rGO) PDCs were ingeniously in-situ constructed. • Re-pyrolysis/graphite-assisted decarburization is a new structural design strategy. • The obtained products own well-balance between thermal insulation and load bearing. • Graphite-assisted interfacial interactions aims at strengthening ceramic framework. • Self-healing effect of SiO 2 can be promptly activated under flame scouring. [ABSTRACT FROM AUTHOR]

Multi-phase UHTCs are favoured for their superior ablation resistance and mechanical properties. In this work, to improve the efficiency and decrease the sintering temperature and pressure, the (Zr, Hf)C and SiC hybrid nanocrystalline particles were prepared via the sol-gel method combining carbothermal reduction at 1600 °C. Utilizing their high sinterability, a relative density of 96.1% (Zr, Hf) C–SiC composite was obtained at the conditions of 1900 °C and 30 MPa using SPS technology. XPS and FT-IR results demonstrate that Zr, Hf, and Si were successfully trapped in the cross-linking structure of the precursors. Precursors of Zr, Hf, and Si reached a molecular-level mixture in the gel phase. SEM, XPS, and XRD characterization showed that the Si–C bond was formed preferentially, leading to the emergence of SiC whiskers and SiC wrapped (Zr, Hf)C with increasing temperature. And, the (Zr, Hf)C can be easily generated during solid solution reaction. Eventually, a nanoscale mixture of (Zr, Hf)C and SiC particles was successfully obtained at 1600 °C. The hardness and compressive strength of the (Zr, Hf)C–SiC composite were 12.94 GPa and 622 MPa, respectively. Comparing usual sintering processes (over 2000 °C and 35 MPa), the reason for the improved sinterability can be attributed to the high sintering activity of the (Zr, Hf)C and SiC hybrid particles, and the existence of the solid solution and nano-SiC. [ABSTRACT FROM AUTHOR]

Although flash sintering (FS) is an effective method for rapidly preparing ceramics, FS of non-oxide ceramics at room temperature (RT) has not yet been achieved. In this study, we developed a feasible method for FS of SiC at room temperature (RT). A dog-bone-shape SiC sample prepared without using any sintering aid achieved a relative density of 96.5 % after sintering in a low-pressure Ar atmosphere for 60 s. Arc heating, which was constrained by the height of an alumina plate fixed above the sample, increased the conductivity of the sample, which then reached the stable stage of FS. The sintered sample exhibited a typical 6H–SiC crystal structure, which was consistent with that of the raw powder. The proposed FS method, based on constraining the arc using an alumina plate under a low-pressure inert gas atmosphere, provides a reference for developing further advanced RT FS strategies for non-oxide ceramics with low conductivities at RT. [ABSTRACT FROM AUTHOR]

The Fenton reaction is known for generating highly reactive hydroxyl radicals that are applied to accelerate the polishing removal rate of chemically inert SiC substrates. However, previous research primarily focuses on the polishing removal rate acceleration on the C surfaces of SiC substrates, and very limited studies have been conducted to investigate whether the hydroxyl radicals produced by the Fenton reaction serve as the primary agents of oxidative activity. Furthermore, the oxidation ability of hydroxyl radicals on the C surface and its relationship with their concentration are still not well-established. Therefore, more extensive research is needed to gain comprehensive understanding on the role of hydroxyl radicals in the oxidative activity on the C surface and their concentration-dependent effects. In this study, the polishing results of alumina, cerium oxide, and silica containing polishing slurries with and without Fenton reaction were compared and analyzed. The material removal rate (MRR) of the C surfaces of SiC substrates was significantly improved after the introduction of the Fenton reaction in alumina-containing slurry at pH 4, resulting in a smoother surface. Low-field nuclear magnetism, atomic force microscopy (AFM), ultraviolet spectrophotometry, and X-ray photoelectron spectroscopy (XPS) were employed to gain insights on inter-particle interactions and oxidation mechanisms of C face of SiC in presence of Fenton reaction. The results revealed that while hydroxyl radicals demonstrated potent oxidation ability, they alone were incapable of oxidizing C face of SiC. [ABSTRACT FROM AUTHOR]

To address the challenge of high-temperature microwave absorbing materials (MAM) for the hot-end components of aircraft, SiC enhanced ZrB 2 –Al 2 O 3 (ZSA) ceramics are prepared by pressureless sintering. In ZSA ceramics, ZrB 2 and SiC are the absorbers and Al 2 O 3 is the matrix. The effect of the content of SiC on microwave absorption properties for the ZSA ceramics are studied. The results show that the addition of SiC enhances the MA properties and high-temperature stability of ZrB 2 –Al 2 O 3 ceramics. Ceramics with an effective absorption bandwidth (EAB) of 3.9 GHz at a thickness of 1.56 mm; and a minimum reflection loss (RL min) of −15 dB is obtained. After treatment at 1000 °C for 20 h in an air atmosphere, the EAB reduces to 3.5 GHz at the thickness of 1.56 mm, however, RL min reaches −21 dB. ZSA ceramics consume microwaves through effect including interfacial polarization relaxation, conductive loss and multiple reflection loss. This work is expected to provide new ideas for the design and development of high-temperature microwave absorbing materials. [ABSTRACT FROM AUTHOR]

With the development of power conversion systems or bidirectional grid-connected inverters characterized by high DC voltage, high efficiency, and high-power density, high-switching-frequency SiC power switches are being widely used, and these require a short computational time of control algorithm. Based on the sector judgment of a space voltage vector and the midpoint potential control balancing of a DC bus, an improved finite control set method prediction control (FCS-MPC) method was proposed for a T-type three-level PCS. This improved FCS-MPC first judges the sector of the space voltage vector and locates the position of the corresponding large sector according to phase lock information; then, it analyzes the sampled voltage of the upper and lower bus capacitors to obtain the midpoint potential situation and selects appropriate small vectors based on the midpoint potential situation. This simple improved strategy can reduce the computational complexity of traditional MPC for rolling optimization, resulting in a reduction in the vectors from 27 to 8. A SiC-based 10 kW bidirectional PCS prototype verified the improved FCS-MPC, and the computational time was reduced about by 56% in comparison to traditional FCS-MPC. [ABSTRACT FROM AUTHOR]

New C/SiC composites with continuous fibers were produced through impregnation of carbon fiber preforms and consolidation by hot pressing. The resulting sintered material was investigated as a potential target for nuclear applications, such as radioisotope production. Desired properties include high porosity and high thermal conductivity to allow isotope release from the targets while working at high temperature. To this end, porosimetry and thermal and mechanical characterizations were conducted up to 1250°C. It was shown that the addition of fibers resulted in high porosity, about 40%, while maintaining a very high thermal conductivity, 40 W/m∙K at 1250°C, a value particularly attractive for the intended application. Emissivity at 1250°C was 0.76, compressive strength at room temperature was 134 MPa, and flexural strength passed from about 90 MPa before thermal conductivity measurements to 50 MPa after the tests. [ABSTRACT FROM AUTHOR]

Silicon carbide (SiC) is a multifunctional material with a myriad of potential applications, from high-power electronics to friction applications to power generation. Grafting preceramic polymers (PCPs) from SiC nanoparticles would create a platform for forming SiC via a polymer derived route that would have advantages over simple particle-PCP slurries and may enable new additive manufacturing inks or spreadable coatings with controlled rheology. Grafting PCPs directly on SiC powders would greatly improve dispersion of these particles and yield a single component system. Moreover, PCP-grafted-SiC would be a new addition to the burgeoning field of polymer grafted nanoparticles (PGNPs). Herein, SiC nanoparticles were surface-modified in a grafting-from polymerization reaction to create polycarbosilane (PCS) grafted SiC. Surface grafting was verified through a number of analytical techniques and the synthesized materials were pyrolyzed at 1600 °C. The PCS-grafted SiC retained 66 % of its pre-pyrolysis mass, representing a significant improvement over PCS-grafted silica nanoparticles from our previous work (20 wt% yield). In addition to an increased ceramic yield, the grafting of PCS to SiC also resulted in the formation of a SiC phase not present in the simple physical mixture of SiC nanopowder in PCS. This study demonstrated that PCP-grafted nanoparticles (GNPs) can be synthesized utilizing non-oxide nanoparticle cores with desirable rheology, opening possibilities for future ceramic inks and coatings. [ABSTRACT FROM AUTHOR]

The Ho-Bi-Te ternary system was studied by DTA, X-ray diffraction, and MSA, as well as by measuring microhardness and determining density, congruent triangulation scheme and projection of the liquidus surface, types and coordinates of mono- and invariant equilibria. It is established that this system is triangulated into five pseudo-ternary systems. It was discovered that an incongruently melting ternary compound containing HoBiTe3 is formed in the Ho-Bi-Te ternary system. X-ray phase analysis established that the HoBiTe3 compound crystallises in a tetragonal system with lattice parameters: a = 19.99, с = 13.82 Å, Z = 3. Studying the nature of the interaction of the components of the quasi-binary section Bi2Te3-Ho2Te3 of the Ho-Bi-Te ternary system, as well as thermoelectric materials formed by combining Bi2Te3 with rare-earth tellurides, is of interest from a scientific and practical point of view. [ABSTRACT FROM AUTHOR]

A comprehensive process model for 4H‐SiC oxidation is created and calibrated against a very large collection of experimental data. The model reproduces measured oxide thickness for Si‐face, C‐face, and a‐face SiC wafers, in the temperature range 950–1500 °C, in the pressure range 0.25–4.0 atm, in the thickness range 3–1600 nm, and for SiC doping ranging between 1019 cm−3 n‐type and 1019 cm−3 p‐type. The model is based on the Massoud model: Oxidation is driven by oxidants (O2, H2O) which are present in the gas phase, diffuse through the oxide, and form SiO2 at the oxide–SiC interface. For thin oxides, the interface reaction rate includes empirical correction terms which add to the oxidation rate, and which asymptotically approach zero with increasing oxide thickness. For dry oxidation, a remarkable dependence on the O2 partial pressure is discovered: For thick oxides, the oxidation rate scales linearly with the pressure, but the correction term for thin oxides scales with the square root of the pressure. This suggests that the atomistic processes responsible for the fast initial growth of oxides involve the splitting of O2 molecules into two O atoms. [ABSTRACT FROM AUTHOR]

The motto of research is to attempt to enrich the mechanical and fracture resistance quality of AA5052 alloy composite composed by the adaptations of 0, 3, 6, and 9 weight percentages (wt%) of silicon carbide (SiC) nanoparticle and 5 wt% of chopped E-glass fiber through vacuum-assisted stir processing under 500 rpm. The metallography analysis of composite samples is analyzed and spots the good interfacial with void-less structure. The composite's mechanical and fracture qualities enriched through the inclusion of SiC (9 wt%) / E-glass fiber (5 wt%) in AA5052 alloy composite attained the highest tensile strength, better hardness, improved elongation percentage and excellent fracture toughness, which is enhanced by 25.5, 33.8, 22, and 15 % comparable to the value of monolithic AA5052 alloy cast. The E-glass configured hybrid AA5052/SiC alloy composite is suggested for automotive body structural applications. [ABSTRACT FROM AUTHOR]

CVD-SiC and sintered SiC (SPS-SiC) were proton irradiated at 340 ̊C receiving different levels of damage (0.05–0.25 dpa). A novel multi-step machining and measurement method using laser flash analysis (LFA) was developed to derive the thermal conductivity of the irradiated layer (∼46 µm). Before irradiation, the thermal conductivity of SPS-SiC was much lower than CVD-SiC, primarily due to its higher intrinsic defect concentration and smaller grain size which provide a greater density of barriers to phonon transmission. Following irradiation, major thermal conductivity degradation (∼90%) was found to occur to both types of SiC after only a low dose (∼0.1 dpa), with both saturating at a similarly low value (a few W/K⋅m), as the thermal resistivity due to the presence of high density of grain boundaries became less important. Thermal conductivity degradation after irradiation was primarily caused by point defects in both types of SiC, as reflected by Raman spectra. [ABSTRACT FROM AUTHOR]

The development of lightweight and high-strength materials is critical for many industries, including aerospace, automotive, and electronics. Metal matrix composites (MMCs) have shown great promise in meeting these requirements. The structural and physical properties of Al6061 alloy reinforced with hybrid MMCs, including TiB2, SiC, and fly ash (FA), were investigated in this research review. The MMCs investigated were made using the stir-casting process. Their microstructure, structural characteristics, and mechanical features were examined. The inclusion of TiB2 and SiC enhanced the composite’s hardness, tensile strength, and wear resistance, while the addition of FA lowered its density and improved its thermal and corrosion resistance. However, the volume percentage, particle dimension, and arrangement of the reinforcing components all had an effect on the physical characteristics of the composite. Therefore, the optimum combination of the reinforcing materials must be carefully selected to achieve the desired properties. The result of this review provides valuable insights into the development of high-performance MMCs for various industrial applications. [ABSTRACT FROM AUTHOR]

This paper reviews sintered silver (s-Ag) die-attach materials for wide band gap (WBG) semiconductor packaging. WBG devices that die-attach with s-Ag have attracted a lot of attention owing to their low energy loss and high temperature operation capabilities. For their practical operation, a reliability design should be established based on the failure of physics of the s-Ag die layer. This paper first focuses on the material characteristics of the s-Ag and tensile mechanical properties. Then, the s-Ag die-attach reliability is assessed with high-temperature storage, power cycling, and thermal shock tests. Each fracture mode was discussed by considering both the fracture surface analysis results and its mechanical properties. Finally, the effective reliability design parameters of the s-Ag die layer are introduced. [ABSTRACT FROM AUTHOR]

This study explores the impact of varying discharge gas compositions on the etching performance of silicon carbide (SiC) in a heptafluoroisopropyl methyl ether (HFE-347mmy)/O2/Ar plasma. SiC is increasingly favored for high-temperature and high-power applications due to its wide bandgap and high dielectric strength, but its chemical stability makes it challenging to etch. This research explores the use of HFE-347mmy as a low-global-warming-potential (GWP) alternative to the conventional high-GWP fluorinated gasses that are typically used in plasma etching. By examining the behavior of SiC etch rates and analyzing the formation of fluorocarbon films and Si-O bonds, this study provides insights into optimizing plasma conditions for effective SiC etching, while addressing environmental concerns associated with high-GWP gasses. [ABSTRACT FROM AUTHOR]

In particular, the impact of Silicon Carbide (SiC) particles on the mechanical properties of stir-cast Al5052 alloy Metal Matrix Composites (MMCs) for rotor blade applications is examined in this work. The goal of integrating SiC particles is to improve mechanical characteristics including wear resistance, tensile strength, and hardness while preserving the ideal weight-tostrength ratio, which is essential for rotor blade performance. The Al5052 matrix was filled with SiC in a variety of compositions (0%, 2%, 4%, 6%, and 8% by weight), and the resultant composites underwent mechanical testing and microstructural examination. Due to the efficient load transfer and reinforcing processes, the results show a considerable improvement in tensile strength and hardness with the addition of SiC particles. Furthermore, microstructural analyses demonstrate a uniform dispersion of SiC in the matrix, which supports the improved performance attributes. Wear resistance of Al5052 alloy is greatly increased when Silicon Carbide (SiC) particles are added as reinforcement. This makes the composite material perfect for applications requiring great durability and longevity to survive hard mining conditions, such as wear plates, conveyor liners, and drill bits in mining machinery components. [ABSTRACT FROM AUTHOR]

The chemical action mechanism in the chemical mechanical polishing of SiC substrate remains elusive, which has great limitations on the selection of polishing solution and polishing parameters. In this paper, the cutting process of unreacted SiC (U–SiC) and the SiC reacted with H 2 O (R-SiC-H 2 O) and H 2 O 2 (R-SiC-H 2 O 2) was studied with an individual diamond abrasive particle by molecular dynamics simulation. The influence of chemical reaction and cutting speed on the material removal of SiC was explored by focusing on the removal rate, surface quality, machining temperature and machining stress. The simulation results showed that the number of removed atoms increased, and the surface roughness and subsurface damage depth decreased for SiC at the same cutting speed after the chemical action. Although the number of removal atoms increased with the increase of cutting speed, the surface roughness and subsurface damage depth increased at the same time. The effects of the polishing medium on the material removal process for SiC can be attributed to the decrease of surface hardness and Si–C bonding energy after the reaction of the polishing medium and SiC. The results provide a guidance for the selection of chemical mechanical polishing systems and machining parameters. • The chemical role of polishing agent is revealed, which helps us master the material removal rules of SiC and increases its material removal rate. • A new phenomenon is found that the dislocation decreases and even disappear with the rise of cutting speed, which may help us obtain damage free SiC. • Load is taken as the controlling factor in polishing. Taking normal load as controlling parameter is in line with the traditional habit in SiC CMP. [ABSTRACT FROM AUTHOR]

Thermoelectric materials that can convert thermal energy to electrical energy are stable and long-lasting and do not emit greenhouse gases; these properties render them useful in novel power generation devices that can conserve and utilize lost heat. SiC exhibits good mechanical properties, excellent corrosion resistance, high-temperature stability, non-toxicity, and environmental friendliness. It can withstand elevated temperatures and thermal shock and is well suited for thermoelectric conversions in high-temperature and harsh environments, such as supersonic vehicles and rockets. This paper reviews the potential of SiC as a high-temperature thermoelectric and third-generation wide-bandgap semiconductor material. Recent research on SiC thermoelectric materials is reviewed, and the principles and methods for optimizing the thermoelectric properties of SiC are discussed. Thus, this paper may contribute to increasing the application potential of SiC for thermoelectric energy conversion at high temperatures. [ABSTRACT FROM AUTHOR]

This study examined the joining of monolithic SiC by Si-C reaction bonding using a 100 µm-thick filler tape prepared using different SiC/C compositions (30/70, 50/50, and 70/30 wt%). Joining was performed at 1450, 1500, and 1550 °C for 1 h in a vacuum without pressure after inserting the filler tape followed by molten-Si infiltration. The sample joined at 1500 °C using a SiC/C = 70/30 filler tape revealed a dense joint morphology without pores or cracks, showing the highest joint strength of 254 MPa. A larger amount of SiC in the filler tape resulted in less residual Si at the joining interface and higher joint strength. Moreover, the distribution of residual stresses at the joint was simulated using finite element analysis, which was well-suited to experimental observations based on micro-Raman spectroscopy. [ABSTRACT FROM AUTHOR]

High efficiency, high quality and green machining of single crystal silicon carbide (SiC) is an important issue in the third-generation semiconductor industry. In this paper, a novel machining method for single crystal SiC based on tribo-oxidation is proposed. The formula and preparation process of polysaccharide bonded soft abrasive tool were designed. Dry machining of C-face of 4H–SiC substrate was carried out with the prepared environmentally friendly abrasive tool sample. The material removal mechanism of the proposed machining method was preliminarily analyzed, and the material removal rate, surface roughness and subsurface residual stress were studied. The experimental results show that the maximum material removal rate of 4H–SiC can reach 1.03 μm/min with a corresponding average surface roughness of S a 0.816 nm. The machined surface has no brittle flaw, and subsurface residual compressive stress exists with a maximum value of 58.9 MPa. The material removal mainly attributed to the active oxidation of SiC surface induced by the friction between alumina abrasives and SiC substrate. The proposed machining method has potential application value in thinning of SiC wafers. [ABSTRACT FROM AUTHOR]

This paper describes results from the mechanical evaluation of unirradiated SiC fiber–reinforced SiC matrix composite tubes under a controlled high-temperature steam environment. The experiments were aimed at identifying key material degradation behavior under environments relevant to loss-of-coolant accidents of light water reactors. Mechanical tests of the SiC composite tubes at 1000 °C under steam and inert environments were conducted using a unique test capability. The material tested was a duplex tube with a thick monolithic SiC layer on the outer surface. The tubes were subjected to preloading at ∼100 MPa in tension before exposure to high-temperature steam with up to 75 % of the preload at a constant displacement. In the presence of matrix cracks, the steam exposure caused embrittlement of the SiC composite tubes and failure at a stress level below the pretest stress. The material degradation was explained by a fiber oxidation model, which can be applied to various SiC cladding concepts. The embrittlement could be a limiting factor for using SiC cladding subjected to loss-of-coolant accident conditions. [ABSTRACT FROM AUTHOR]

A rapid, cost-effective and eco-friendly approach for fabricating SiC using Si particles derived from Si scrap is highly recommended from both economic and environmental standpoints. Herein, we demonstrate the fabrication of β-SiC effectively in argon atmosphere at 1500°C by utilizing combustion synthesis followed by flash sintering in a single-step experiment for the first time. Synthesis of β-SiC was relied on exothermic reaction between Si and C elements present in the powder compact whereas densification was accomplished eventually through flash sintering. In addition, the effects of different flash sintering conditions on the properties of β-SiC are examined with and without Y 2 O 3 sintering additive. A high relative density of 85% was realized when a current density of 60 mA/mm2 was applied for 60 min with Y 2 O 3 addition. This novel one-step fabrication approach has the potential to reduce production cost of β-SiC significantly and has both commercial and environmental advantages. [ABSTRACT FROM AUTHOR]

The realm of vehicular safety applications driven by communication has surfaced as a paramount approach for elevating road safety standards. The adoption of Vehicular VLC (V-VLC) is rooted in its multifaceted advantages, making it a preferred choice for integrating both illumination and data transmission. Beyond its highly secure attributes, V-VLC boasts virtues such as demonstrating low complexity, and ensuring immunity to radio frequency (RF) interference. The core premise of this study revolves around the proposition of a novel system that synergistically integrates NOMA into V-VLC networks to amplify spectral efficiency, harnesses beamforming techniques to bolster Signal-to-Noise Ratio (SNR), and leverages Successive Interference Cancellation (SIC) to curtail interference. An exhaustive analysis of this system configuration is provided, accompanied by the derivation of a precise Signal-to-Interference-plus-Noise Ratio (SINR) expression tailored to the proposed scenario. This paper not only delves into the nuanced aspects of NOMA performance at the receiver but also delves into critical dimensions such as the influence of transmitter-receiver distance, elevation disparity between transmitter and receiver, and the impact of diverse channel conditions on received power and BER VS. Eb/No for different MIMO configurations. [ABSTRACT FROM AUTHOR]

To realize precise directional spectral emissivity determination of solid materials under the atmosphere, an apparatus what covers the temperature region from 50 °C to 1000 °C and a spectral range of 3 μm–14 μm was developed. The measurement angle can be adjusted from 0° to 60° utilizing a stepper rotary stage. The reliability of the apparatus's reliability was confirmed by measuring the spectral emissivity of a SiC sample at high temperatures. Furthermore, the normal spectral emissivity of SiC was investigated from 50 °C to 1000 °C, and the directional spectral emissivity at 600 °C and 800 °C was shown. The influence of temperature and measurement angle on the spectral emissivity of SiC was analyzed in detail. Additionally, the cause of the silicon dioxide film on the surface of SiC after high temperature heating and its influence on spectral emissivity were explored. Finally, a detailed analysis of the uncertainty components of the emissivity measurement under varying temperatures and wavelengths was performed, and the results showed that the uncertainty of the apparatus was better than 0.05 in its measurement range. [ABSTRACT FROM AUTHOR]

Super-reduced phases (SRPs), such as silicon carbide (SiC) and metal silicides, have increasingly been reported in various geological environments. However, their origin remains controversial. SRP inclusions (e.g., metal silicides and metallic silicon (Si0)) within SiC are commonly believed to indicate a natural origin. Here, we identified an unusual SRP assemblage (SiC, (Fe,Ni)Si2, and Si0) in situ in an H5-type Jingshan ordinary chondrite. Simultaneously, our analysis showed that the SiC abrasives contain (Fe,Ni)Si2 and Si0 inclusions. Other inclusions in the artificial SiC were similar to those in natural SiC (moissanite) reported in reference data, including diverse metal silicides (e.g., FeSi, FeSi2, Fe3Si7, and Fe5Si3), as well as a light rare earth element-enriched SiO phase and Fe-Mn-Cr alloys. These inclusions were produced by the in situ reduction of silica and the interaction between Si-containing coke and hot metals during the synthesis of the SiC abrasives. The results demonstrate that the SRP assemblage in the Jingshan chondrite originates from abrasive contamination and that the SRP inclusions (with a low content of Ca, Al, Ti, and Zr) cannot be used as a conclusive indicator for natural SiC. Additionally, the morphologies, biaxiality, and polytypes (determined by Raman spectroscopy) of SiC abrasives bear resemblance to those reported for natural SiC, and caution must be exercised when identifying the origin of SRP in samples processed by conventional methods using SiC abrasives. At the end of this paper, we propose more direct and reliable methods for distinguishing between natural and synthetic SiC. [ABSTRACT FROM AUTHOR]

In this study, mechanical grinding, chemical surface treatment and copper electroplating were adopted to treat the inner surface of the outer A356 layer of the A356/A356-10SiCp double-layer cylinder liner. The effects of different surface treatments on the microstructure and mechanical properties of the composite interface were investigated. The results show that the composite interface treated with mechanical grinding is bonded mechanically because of the secondary oxidation on the inner surface of the outer A356 aluminum alloy cylinder liner, and there are many gaps at the interface, resulting in a compromised interfacial bonding strength of merely 4.05 MPa. Both the chemical method and copper electroplating surface treatments effectively inhibited the secondary oxidation on the internal surface of the outer A356 aluminum alloy cylinder liner, enhancing interfacial wettability. The microstructure revealed no discernible gaps at the composite interface, achieving a good metallurgical bonding interface. Notably, the shear fracture surface of the copper electroplated treatment exhibited minimal oxide and inclusions, resulting in superior interface bonding strength of 13.27 MPa which is higher than that of the chemical surface treatment of 6.37 MPa. [ABSTRACT FROM AUTHOR]

A silicon carbide (SiC) plasma has been produced by a Q-switched laser at 1064 nm, 3 ns pulse and 1010 W/cm2 intensity, in high vacuum to investigate the fundamental mechanisms of laser-semiconductor interaction. Although the high hardness and chemical stability restrain the SiC micromachining, it is a valuable semiconductor for devices working under extreme conditions.The plasma has been characterized by using time-of-flight (TOF) measurements of ions detected by an ion collector ring (ICR) and an ion energy analyzer (IEA). Fast CCD camera, quadrupole mass spectroscopy (QMS) and surface profiler have been employed to provide deep insights into the laser-SiC interaction mechanisms.Ion kinetic energies, charge states, plasma expansion velocity, ablation yield per laser pulse, plasma temperature and density have been measured.Applications of the laser-generated plasma are presented and discussed. [ABSTRACT FROM AUTHOR]

The correlations between the electrical behavior and microstructural properties of samples consisting of particle composites fabricated from SiC particles embedded in a silicone matrix, were investigated using X-ray computed tomography. In the voltage field range 200-1000 V/mm, the measured conductivity as a function of SiC volume fraction exhibits two distinct gaps. Upon further investigations, we attribute these observations to percolation thresholds at the microscale. The first gap, corresponding to interconnections between SiC particles that were originally disconnected, is more significant at higher voltage; while the second one, resulting from shortening conductivity pathways between the external surfaces of the samples with the increase of SiC volume fraction, seems more sensitive to lower voltages and is correlated with a decrease of the tortuosity of the percolated SiC network. [ABSTRACT FROM AUTHOR]

The strong covalent bonding of SiC makes it difficult to be fully sintered using conventional sintering techniques. Therefore, electrical current-assisted sintering techniques such as spark plasma sintering are needed to sinter SiC. The finite numerical simulations have been generally used to predict and guide sintering processes of ceramics (i.e.TiC,AlO 3). In this work, the numerical simulations of the temperature distribution, electrical field and thermal field on the porous SiC cylindrical samples by Comsol were investigated in details. The influence of porosity on the temperature distribution and electrical field distribution of the SiC samples were analyzed. Both the maximum current density (1.19 × 107A/m2) and the maximum temperature (2030 °C) of the SPS device occurred at the punch/spacer interface. The temperature values at the centre of the samples were proportional to the porosity, and the temperatures at the center of the samples increased from ∼1960 °C to ∼2010 °C at t = 2000s, with the porosity increasing from 1% to 60%. The uniformity of the temperature distribution deteriorated as the porosity increases, and the temperature gradients between the center and edge of the samples with the porosity of 1% and 60%, were ∼80 °C and ∼130 °C at t = 2000s, respectively. [ABSTRACT FROM AUTHOR]

SiC ceramics are typically hard and brittle materials. Serious surface/subsurface damage occurs during the grinding process due to the poor self-sharpening ability of monocrystalline diamond grits. Nevertheless, recent findings have demonstrated that porous diamond grits can achieve high-efficiency and low-damage machining. However, research on the removal mechanism of porous diamond grit while grinding SiC ceramic materials is still in the bottleneck stage. A discrete element simulation model of the porous diamond grit while grinding SiC ceramics was established to optimize the grinding parameters (e.g., grinding wheel speed, undeformed chip thickness) and pore parameters (e.g., cutting edge density) of the porous diamond grit. The influence of these above parameters on the removal and damage of SiC ceramics was explored from a microscopic perspective, comparing with monocrystalline diamond grit. The results show that porous diamond grits cause less damage to SiC ceramics and have better grinding performance than monocrystalline diamond grits. In addition, the optimal cutting edge density and undeformed chip thickness should be controlled at 1–3 and 1–2 um, respectively, and the grinding wheel speed should be greater than 80 m/s. The research results lay a scientific foundation for the efficient and low-damage grinding of hard and brittle materials represented by SiC ceramics, exhibiting theoretical significance and practical value. [ABSTRACT FROM AUTHOR]

Concerning various materials in the engineering domain, magnesium alloy-based composites are found to have specific properties. They are prepared with ceramic particles via a liquid stirring process, and oxidation results in porousness. Due to this, this research aims to develop cast magnesium alloy (AZ80), nanocomposite and hybrid nanocomposites via a liquid state stir casting process with an argon atmosphere. It contains 0, 2, 4 and 6 wt% of silicon carbide nanoparticles (SiC) and 6 wt% SiC with 3, 6 and 9 wt% of basalt fibre. The developed cast AZ80 alloy, nano and hybrid nanocomposites are subjected to physical, mechanical and wear behaviour studies, and their results are compared. The composite contained 6 wt% SiC, and 9 wt% BF showed low porosity (1.03%), superior tensile strength (359 ± 7 MPa), elastic modulus (23044.58 ± 230 MPa), strain (2.114 ± 0.01 mm), hardness (121 ± 1.02 HV), coefficient of friction (0.421 ± 0.02) and low impact strength (18.25 ± 0.34 J/mm2) and volumetric wear rate (5.36 ± 0.4 mm3/m) compared to others. [ABSTRACT FROM AUTHOR]

This research affair to synthesize the magnesium alloy (AZ91) hybrid nanocomposites with 0.5wt% titanium dioxide (TiO2) and 2.5, 5, and 7.5wt% of silicon carbide (SiC) nanoparticles through a semisolid stir cast route under argon (inert) nature and its particle distribution enhanced with uniform stir speed of 400rpm as well as the casting defects reduced by using nature of inert. The excellence of semisolid stir processing with SiC exposure on AZ91/TiO2 composite is analyzed with physical, surface morphological and mechanical exploits. Compared to aluminium-based composites, this composite weight is less, with an acceptable level of voids (less than 1.5%). An effort of processing, the microstructure proved their SiC and TiO2 appearance as uniform. The AZ91/0.5wt%TiO2/7.5wt% SiC exploited maximum hardness of (84±0.8HV), impact toughness of (16.3±0.3J/mm2), and excellent strength (251±5MPa) with reduced elongation percentages of (4.5%). This optimum property sample will be planned for automotive roof frame applications. [ABSTRACT FROM AUTHOR]