Microstructure and strengthening behavior in high content SiC nanowires reinforced SiC composites

In this study, the high-content SiC_nw reinforced SiC ceramic matrix composites (SiC_nw/SiC CMC) were successfully fabricated by hot pressing β-SiC and sintering additive (Al₂O₃-Y₂O₃) with boron nitride interphase modification SiC_nw. The effects of sintering additive content and mass fraction (5–25 wt%) of SiC_nw on the density, microstructure, and mechanical properties of the composites were investigated. The results showed that with the increase of sintering additives from 10 wt% to 12 wt%, the relative density of the SiC_nw/SiC CMC increased from 97.3% to 98.9%, attributed to the generated Y₃Al₅O₁₂ (YAG) liquid phase from the Al₂O₃-Y₂O₃ that promotes the rearrangement and migration of SiC grains. The comprehensive performance of the obtained composite with 15 wt% SiC_nw possessed the optimal flexural strength and fracture toughness of 524 ± 30.24 MPa and 12.39 ± 0.49 MPa·m^1/2, respectively. Besides, the fracture mode of the composites with 25 wt% SiC_nw content revealed a pseudo-plastic fracture behavior. It concludes that the 25 wt% SiC_nw/SiC CMC was toughened by the fiber pull-outs, debonding, bridging, and crack deflection that can consume plenty of fracture energy. The strategy of SiC nanowires worked as a main bearing phase for the fabrication of SiC/SiC CMC providing critical information for understanding the mechanical behavior of high toughness and high strength SiC nanoceramic matrix composites.     

Si-rich pressureless sintering of the gelcasted Ti3SiC2 bulk ceramic

The Si-rich pressureless sintering was used to fabricate the Ti₃SiC₂ bulk ceramic. The results show that the optimized Ti₃SiC₂ suspension could be prepared at the absolute value of zeta potential, pH level, PAA-NH₄ dosage, and solid loading of 62.1 mV, 11, 2.0 wt%, and 50 vol%, respectively. The channels existing in the Si-free sintered body facilitated the reactants and products to diffuse to the interior and out of the Ti₃SiC₂ matrix, thereby forming the porous reaction layer of TiC-Ti₃SiC₂. The co-effects of the channels and the reaction layer of TiC-Ti₃SiC₂ severely lowered mechanical properties of the Si-free sintered Ti₃SiC₂ ceramic. On the contrary, the Si-rich sintering method isolated the volatile carbon and established a closed Si-rich atmosphere to sinter the green Ti₃SiC₂ cylinder. The porosity, density, fracture toughness, hardness, and flexural strength of the Si-rich sintered Ti₃SiC₂ ceramic reached 0.74 vol%, 4.36 g/cm³, 5.49 MPa·m^1/2, 4.03 GPa, and 383 MPa, respectively.     

Preparation,mechanical properties,and toughening mechanisms of SiCw/SiCp-reinforced zirconia-toughened alumina ceramics

Zirconia-toughened alumina (ZTA) ceramics with high mechanical properties were sintered by hot-pressing method using SiC particles (SiCp) and SiC whiskers (SiCw) as the reinforcing agents simultaneously. The influences of sintering temperature, SiCp, and SiCw contents on the microstructure and mechanical properties of ZTA ceramics were investigated. It was found that both SiCp and SiCw could contribute to grain refinement significantly and promote the mechanical properties of the ceramics. However, the excess addition of SiCp or SiCw led to the formation of pores with large sizes and degraded the mechanical properties instead. When 13 wt% SiCp was introduced, the maximum flexural strength of 1180.0 MPa and fracture toughness of 15.9 MPa·m^1/2 were obtained, whereas the maximum flexural strength of 1314.0 MPa and fracture toughness of 14.7 MPa·m^1/2 were achieved at 20 wt% SiCw. Interestingly, the simultaneous addition of SiCp and SiCw could further improve the mechanical properties, and the highest flexural strength of 1334.0 MPa and fracture toughness of 16.0 MPa·m^1/2 were achieved at a SiCw/SiCp ratio of 16/4. The reinforcement mechanisms in the ceramics mainly included the phase transformation toughening of ZrO₂, the crack deflection and bridging of SiCp and SiCw, and the pull-out of SiCw.     

Mechanical properties of silicon carbide—in situ zirconium carbonitride composites

SiC–Zr₂CN composites were fabricated by conventional hot pressing from β-SiC and ZrN powders with 2 vol% equimolar Y₂O₃–Sc₂O₃ as a sintering additive. The effects of the ZrN addition on the room-temperature (RT) mechanical properties and high-temperature flexural strength of the SiC–Zr₂CN composites were investigated. The fracture toughness gradually increased from 4.2 ± 0.3 MPa·m^1/2 for monolithic SiC to 6.3 ± 0.2 MPa·m^1/2 for a SiC–20 vol% ZrN composite, whereas the RT flexural strength (546 ± 32 MPa for the monolithic SiC) reached its maximum of 644 ± 87 MPa for the SiC–10 vol% ZrN composite. The monolithic SiC had improved strength at 1200°C, whereas the SiC–Zr₂CN composites could not retain their RT strengths at 1200°C. The typical flexural strength values of the SiC–0, 10, and 20 vol% ZrN composites at 1200°C were 650 ± 53, 448 ± 31, and 386 ± 19 MPa, whereas their RT strength values were 546 ± 32, 644 ± 87, and 528 ± 117 MPa, respectively.     

Combustion synthesis of SiC-based ceramics reinforced by discrete carbon fibers with in situ grown SiC nanowires

This study proposes a combustion-based ceramic matrix composite processing technique intended on single-step in situ deposition of single-crystal SiC nanowires (SiC_nw) on the surface of carbon fibers (C_f) and formation of SiC_nw–reinforced SiC matrix. This was accomplished by Ta-catalyzed combustion of poly-(C₂F₄)-containing reactive mixtures with pre-mixed chopped C_f. Depending on the combustion conditions, carbon fiber surface is subjected either to formation of diffusion layers, ceramic particle incrustation or growth of continuous arrays of carbon-coated single-crystal SiC_nw with a nearly defect-free lattice, 10–50 nm diameter and 15–20 μm length. Thermodynamics, phase and structure formation mechanisms are explored, and the optimal conditions are outlined for reproducible C_f/in situ SiC_nw dual reinforcement of SiC-based ceramics. Hot pressing at 1500 °C produced C_f/in situ SiC_nw-reinforced ceramic SiC–TaSi₂ specimens with a relative density of 97%, 19 GPa Vickers hardness, 3-point flexural strength σ = 420 ± 70 MPa and fracture toughness K_1C = 12.5 MPa m^1/2.     

Fabrication and properties of SiCnw-reinforced SiC composites by reactive melt infiltration with BN and PyC interface

To tailor the fiber–matrix interface of SiC nanowires-reinforced SiC (SiC_nw/SiC) ceramic matrix composites (CMCs) for improved mechanical properties, SiC nanowires were coated with BN and pyrolytic carbon (PyC) compound coatings prepared by the dip-coating process in boric acid and urea solution and the pyrolysis of phenolic resin. SiC_nw/SiC CMC with PyC/BN interfaces were fabricated by reactive melt infiltration (RMI) at 1680°C for 1 h. The influences of phenolic resin content on the microstructure and mechanical properties of the CMC were investigated. The results showed that the flexural strength and fracture toughness reach the maximum values of 294 MPa and 4.74 MPa m^1/2 as the phenolic resin content was 16 and 12 wt%, respectively. The displacement–load curve of the sample exhibited a gradient drop with increasing phenolic resin content up to 12 wt%. The results demonstrated that the PyC/BN compound coatings could play the role of protecting the SiC_nw from degradation as well as improving the more moderate interfacial bonding strengths during the RMI.     

Ultra-light 3D bamboo-like SiC nanowires felt for efficient microwave absorption in the low-frequency region

Nonmagnetic ceramics are ideal microwave absorbing materials used in high-temperature and oxidizing environments. However, low-frequency absorbing properties of this material are rarely reported because low-frequency absorbing requires nonmagnetic materials to have much higher permittivity. In this research, a series of three-dimensional architectures formed by SiC nanowires with different microstructures felt were fabricated to address this issue. The morphology of the SiC_nw (linear, bamboo-shaped, and worm-like) dominated by the VLS growth mechanism can be manipulated by the silicon vapor concentration, which is governed by the vaporization temperature of the mixed silicon source (Si and SiO₂) in different sintering processes. The spontaneously overlapped bamboo-shaped SiC nanowires in these felt enhance the permittivity and conductivity loss and produce multiple scattering effects on the incident EM waves, thus increasing the low-frequency wave absorption ability. The RL_min of the bamboo-shaped SiC_nw felt reaches ?44.3 dB at 3.85 GHz with the corresponding EAB of 0.64 GHz (3.6–4.24 GHz) at a thickness of 3.5 mm. The density of the SiC_nw felt is as low as 0.022 g/cm³ due to the high porosity (99.3%) of 3D networks, which fulfills lightweight requirements and highly efficient electromagnetic wave absorption.     

Low-temperature sintered (Ti,Zr, Nb,Ta, Mo)C-based composites toughened with damage-free SiCw

The high sintering temperature would have a great tendency to damage the morphology and thus properties of the silicon carbide whisker (SiC_w) in high entropy carbide-silicon carbide whisker (HEC-SiC_w) composites, which, in turn, would impact the effectiveness of the operative toughening mechanisms. The objective of this study was to achieve full contributions to the toughening effects of SiC_w by preparing (Ti, Zr, Nb, Ta, Mo)C-SiC_w composites at low temperature (1600 ℃) using cobalt as additives. Results showed that the fracture toughness of the (Ti, Zr, Nb, Ta, Mo)C bulk reinforced with 20 vol% SiC_w and 5 vol% Co was 7.2 MPa?m^1/2, which was much higher than that of the (Ti, Zr, Nb, Ta, Mo)C bulk only sintered with 5 vol% Co (3.4 MPa?m^1/2). Meanwhile, it was also higher than that of the reported HEC-20 vol% SiC_w composite sintered at 2000 ℃ (4.3 MPa?m^1/2). For the fracture toughness of HEC-SiC_w composites, it was significantly increased by the introduction of damage-free SiC_w.     

Preparation and mechanical properties of SiCw-reinforced WC-10Ni3Al cemented carbide by microwave sintering

SiC_w-reinforced WC-10Ni₃Al cemented carbide was prepared by microwave sintering method, and the effects of the sintering temperature and SiC_w content on the microstructure and mechanical properties of WC-10Ni₃Al cemented carbide were investigated; the promotion effect and strengthening mechanism of SiC_w were then analysed. The experimental results showed that the relative density, hardness, flexural strength and fracture toughness of WC-10Ni₃Al cemented carbide increased and then decreased with increasing SiC_w addition and sintering temperature. When the sintering temperature was 1500 °C and the content of SiC_w was 0.3 wt%, the sample reached the highest mechanical properties and had a relative density of 96.5%, hardness of 1570 HV, flexural strength of 1275 MPa and fracture toughness of 13.1 MPa mm^1/2, which were 4.0%, 23.1%, 12.5% and 8.1% higher than those of the sample without SiC_w, respectively. During microwave sintering of WC-Ni₃Al, the addition of an appropriate SiC_w content can increase the microwave absorption of the sample, and produce many micro-high-temperature regions within the sample, which can accelerate the generation of the Ni₃Al liquid phase. This promotes liquid phase flow to fill pores and rearrange the WC grains, thereby improving density and mechanical properties of the sample. The strengthening mechanisms of SiC_w on microwave sintered WC-Ni₃Al consist of promoting densification enhancement, fine-grained strengthening, and solid solution strengthening of Ni₃Al by Si atoms.     

Preparation of SiC/SiC composites with high toughness by reaction of the SiCP+C double-cladding layer with liquid silicon

SiC/SiC composites prepared by liquid silicon infiltration (LSI) have the advantages of high densification, matrix cracking stress and ultimate tensile strength, but the toughness is usually insufficient. Relieving the residual microstress in fiber and interphase, dissipating crack propagation energy, and improving the crystallization degree of interphase can effectively increase the toughness of the composites. In this work, a special SiC particles and C (SiC_P +C) double-cladding layer is designed and prepared via the infiltration of SiC_P slurry and chemical vapor infiltration (CVI) of C in the porous SiC/SiC composites prepared by CVI. After LSI, the SiC generated by the reaction of C with molten Si combines with the SiC_P to form a layered structure matrix, which can effectually relieve residual microstress in fiber and interphase and dissipate crack propagation energy. The crystallization degree of BN interphase is increased under the effects of C-Si reaction exotherm. The as-received SiC/SiC composites possess a density of 2.64 g/cm³ and a porosity of 6.1%. The flexural strength of the SiC/SiC composites with layered structure matrix and highly crystalline BN interphase is 577 MPa, and the fracture toughness reaches up to 37 MPa·m^1/2. The microstructure and properties of four groups of SiC/SiC composites prepared by different processes are also investigated and compared to demonstrate the effectiveness of the SiC_P +C double-cladding layer design, which offers a strategy for developing the SiC/SiC composites with high performance.     

Fabrication of in-situ Ti-Cx-N1−x phase enhanced porous Si3N4 absorbing composites by gel casting

In view of the lack of a conformal, load-bearing, lightweight, and high-temperature resistant integrated microwave-absorbing composites for applications under extremely complex conditions, this study successfully applies gel casting craft to porous Si₃N₄ microwave-absorbing composites. The high-temperature decomposition reaction of Ti₃SiC₂ powder was utilized to generate uniform Ti-C_x-N_1−x grains in situ and to enhance the mechanical and microwave-absorption properties of porous Ti-C_x-N_1−x/Si₃N₄ composites. The bending strength, fracture toughness, density, maximum reflection loss value, absorption bandwidth and matched thickness in P-band of the composite with 30 wt% Ti₃SiC₂ addition were 164.87 ± 7.56 MPa, 2.61 ± 0.13 MPa·m^1/2, 2.077 g/cm³, 32.42 dB, 1.74 GHz and 4.2 mm, respectively. The fracture toughness and bending strength of the composite were increased by 71.71% and 58.13%, respectively, compared with monolithic porous Si₃N₄. The electromagnetic wave loss mechanisms of the composites are proposed as a combination of conductivity loss, multiple reflections and scattering, interfacial polarization and defect polarization.     

Multidimensional nano-graphite constructed TiB2–SiC–B4C composite ceramics with the integration of mechanical and electromagnetic properties

The goal of this study is to create structure-functional integrated ceramic matrix composites with high structural strength and electromagnetic absorbing properties. The multidimensional nano-graphite (1-Dimensional rod-like nano-graphite, 0-Dimensional dispersive nano-graphite, and 2-Dimensional lamellar nano-graphite) were employed to construct TiB₂–SiC–B₄C composites via high-energy ball milling, vacuum filtration, and reactive SPS sintering. The microstructure of multidimensional nano-graphite was investigated using XRD and HRTEM and determined to be a crystal-amorphous coexisting. Furthermore, solid solution reaction and interfacial evolution are confirmed as the primary influence on the microstructure of TiB₂–SiC–B₄C composite. A significant improvement occurs on the flexural strength (647.6 MPa) and bending toughness (5.1 MPa m^1/2). Meanwhile, the multi-dimensional nano-graphite gives the TiB₂–SiC–B₄C composite the loss ability of electromagnetic waves, and the matching thickness of the 10 vol% sample is 2.4 mm and the absorption range is 10.4–11.3 GHz.     

Fabrication of TiC coated short carbon fiber reinforced Ti3SiC2 composites: Process,microstructure and mechanical properties

The C_f/Ti₃SiC₂ composites were fabricated through spark plasma sintering (SPS) and hot isostatic pressing (HIP), TiC coated C_f and Ti₃SiC₂ powder were used as starting materials. The improved fracture toughness (K_IC) and Vickers hardness (HV₁) of the TiC coated C_f/Ti₃SiC₂ composite fabricated by SPS were 7.59 MPa·m^1/2 and 7.28 GPa. On this foundation, taking the advantage of better sintering process of HIP, the highest K_IC and HV₁ achieved 8.32 MPa·m^1/2 and 9.24 GPa with fiber content of 10 vol%, which increased by 40% and 65% compared with that of monolithic Ti₃SiC₂. The reasonable control of reactive interface is the main factor for the improved mechanical properties of the composites, the TiC coating effectively protected the fiber structure from interfacial reaction compared with that of the non-coated C_f/Ti₃SiC₂. Meanwhile, the artificially designed and weakly bonded TiC coated C_f can fully exert the toughening mechanisms like fiber pull-out and debonding.     

Processing and properties of polycrystalline cubic boron nitride reinforced by SiC whiskers

Dense polycrystalline cBN (PcBN)–SiCw composites were fabricated by a two-step method: First, SiO₂ was coated on the surface of cubic boron nitride (cBN) particles by the sol-gel method. Then, silicon carbide whisker (SiC_w)- coated cBN powder was prepared by carbon thermal reaction between SiO₂ and carbon powders at 1500°C for 2 hour. Then, cBN–SiC_w complex powders were sintered by high-pressure and high-temperature sintering technology using Al, B, and C as sintering additives. The phase compositions and microstructures of cBN–SiC_w composites were investigated by X-ray diffraction and scanning electron microscopy, respectively. It was found that the SiC_w and Al₃BC₃ had been fabricated by in situ reaction, which cannot only promote densification but also improve mechanical properties. The relative density of PcBN composites increased from 96.3% to 99.4% with increasing SiC_w contents from 5 to 20 wt%. Meanwhile, the Vickers hardness, fracture toughness and flexural strength of as-obtained composites exhibited a similar trend as that of relative density. The composite contained 20 wt% of SiC_w exhibited the highest Vickers hardness and fracture toughness of 42.7 ± 1.9 GPa and 6.52 ± 0.21 MPa•m^1/2, respectively. At the same time, the flexural strength reached 406 ± 21 MPa.     

Effects of SiC nanowires and whiskers on high-entropy carbide-based composites sintered at low and high temperatures

This study aimed to investigate the toughening effects of SiC nanowires (SiC_nw) and SiC whiskers (SiC_w) on high-entropy carbide based composites prepared at different temperatures (1600°C and 2000°C). At low temperature (1600°C), SiC_nw and SiC_w maintain their original morphology and properties, and exhibit the good toughening effects. The SiC_nw with larger aspect ratio and more curly wires exhibit a much stronger toughening effect on the (Ti_0.2Zr_0.2Nb_0.2Ta_0.2Mo_0.2)C_0.8 composites reinforced with 15 vol.% SiC_nw, which shows the highest value of fracture toughness about 6.7 MPa∙m^1/2. However, at high sintering temperature (2000°C), SiC_nw and SiC_w are prone to thermal-induced damages, which significantly reduces their mechanical properties, and thus, toughening effects on (Ti_0.2Zr_0.2Nb_0.2Ta_0.2Mo_0.2)C_0.8 composites. The addition of SiC_w, which have better thermal stability at 2000°C, results in the (Ti_0.2Zr_0.2Nb_0.2Ta_0.2Mo_0.2)C_0.8–15 vol.% SiC_w composite exhibiting relatively better fracture toughness, about 3.7 MPa∙m^1/2. Based on the results of the current study, the critical influence of SiC_nw and SiC_w on the toughening of (Ti_0.2Zr_0.2Nb_0.2Ta_0.2Mo_0.2)C_0.8 composites is highly dependent on their high-temperature thermal stability.     

Processing and properties of cordierite-silica bonded porous SiC ceramics

Cordierite-silica bonded porous SiC ceramics were fabricated by infiltrating a porous powder compact of SiC with cordierite sol followed by sintering at 1300–1400 °C in air. The porosity, average pore diameter and flexural strength of the ceramics varied 30–36 vol%, ~ 4–22 µm and ~ 13–38 MPa respectively with variation of sintering temperature and SiC particle sizes. In the final ceramics SiC particles were bonded by the oxidation-derived SiO₂ and sol-gel derived cordierite. The corrosion behaviour of sintered SiC ceramics was studied in acidic and alkaline medium. The porous SiC ceramics were observed to exhibit better corrosion resistance in acid solution.     

Pressureless sintered silicon carbide matrix with a new quaternary additive for fully ceramic microencapsulated fuels

This study suggests a new additive composition based on AlN–Y₂O₃–Sc₂O₃–MgO to achieve successful densification of SiC without applied pressure at a temperature as low as 1850 °C. The typical sintered density, flexural strength, fracture toughness, and hardness of the SiC ceramics sintered at 1850 °C without applied pressure were determined as 98.3%, 510 MPa, 6.9 MPa·m^1/2, and 24.7 GPa, respectively.Fully ceramic microencapsulated (FCM) fuels containing 37 vol% tristructural isotropic (TRISO) particles could be successfully sintered at 1850 °C using the above matrix without applied pressure. The residual porosity of the SiC matrix in the FCM fuels was only 1.6%. TRISO particles were not damaged during processing, which included cold isostatic pressing under 204 MPa and sintering at 1850 °C for 2 h in an argon atmosphere. The thermal conductivity of the pressureless sintered FCM pellet with 37 vol% TRISO particles was 44.4 Wm^?1 K^?1 at room temperature.     

Preparation,mechanical and thermal properties of Si3N4 ceramics by gelcasting using low–toxic DMAA gelling system and gas pressure sintering

In this work, Si₃N₄ ceramics were fabricated through an aqueous gelcasting method using a low–toxic monomer called N, N–dimethylacrylamide (DMAA) followed by gas pressure sintering at 1850 °C for 2 h under 6 MPa N₂ atmosphere. The effect of solid loading on performance of slurries, green and sintered bodies was investigated systematically. The results show that the slurries with a solid loading as high as 50 vol% (viscosity 0.17 Pa.s at 100 s^–1) were achieved. With the increase of solid loading (30–50 vol%), the green bodies exhibited a monotonically decreased, however high enough in general, flexural strength of 16.50–11.52 MPa, which was comparable to that of widely–used neurovirulent acrylamide (AM) gelling system. In regard to the sintered bodies, increasing solid loading significantly promoted sintering and improved mechanical properties and thermal conductivity as a result of the increased density, bimodal distribution structure, as well as suitable interfacial bonding strength. The best performance parameters of Si₃N₄ ceramics, bulk density of 3.25 g/cm³, apparent porosity of 0.67%, flexural strength of 898.92 MPa, fracture toughness of 6.42 MPa m^1/2, Vickers hardness of 2.81 GPa, and thermal conductivity of 34.69 W m^–1 K^–1, were obtained at 50 vol% solid loading. This work renders low–toxic DMAA gelling system promising prospect in preparation of high–performance Si₃N₄ ceramics by gelcasting.     

Sintering behavior and mechanical properties of Ta4HfC5-based composites with ZrB2 additive

Ta₄HfC₅ powder was synthesized using TaCl₅, HfCl₄ and phenolic resin as raw materials. Then, Ta₄HfC₅–10 vol% MoSi₂ ceramics and Ta₄HfC₅–10 vol% MoSi₂ with different proportions of ZrB₂ (10 – 30 vol%) ceramics were sintered by spark plasma sintering. Zr atoms substituted Ta and Hf atoms in Ta₄HfC₅ during the sintering process at 2000 °C. The sintering behavior and microstructure evolution upon the ceramics are discussed. The mechanical properties of the composites were improved compared to the pure Ta₄HfC₅ ceramics. The hardness of Ta₄HfC₅–MoSi₂ with 30 vol% ZrB₂ increased from around 10 GPa to almost 13 GPa, the flexural strength increased from around 245–435 MPa, and the fracture toughness increased from 2.56 ± 0.12 MPa?m^1/2 to 4.46 ± 0.20 MPa?m^1/2.     

Influence of TiB2 content on the properties of TiC–SiCw composites

The impact of various volume percentages of TiB₂ additive (0, 10, 20, and 30) on the microstructure, relative density (RD), Vickers hardness, flexural strength, and thermal conductivity of as-sintered TiC-10 vol% SiC_w-based composite samples were scrutinized. All four samples were sintered using the SPS method under the following circumstances; sintering temperature of 1900 °C, dwell time of 7 min, and external pressure of 40 MPa. The best relative density of 98.73% was achieved for the sample with no TiB₂ additive, indicating the negative effect of TiB₂ additive on the RD and formation of porosity. The microstructural observations and XRD results confirmed the chemical interaction of TiO₂ and B₂O₃ oxide layers and SiC_w and in-situ formation of the TiSi brittle phase and TiC. The most significant values of flexural strength (511 MPa) and hardness (27.67 GPa) were related to TiC-10 vol% SiC_w and TiC-10 vol% SiC_w-30 vol% TiB₂ samples, respectively. On the contrary, the specimens with 30 vol% and 10 vol% TiB₂ as additive presented the poorest qualities of flexural strength (234 MPa) and Vickers hardness (22.12 GPa). Finally, the influence of the TiB₂ content on the thermal conductivity was evaluated, indicating the positive impact of this secondary phase on this characteristic, so with adding 30 vol% TiB₂ to TiC-10 vol% SiC_w, a thermal conductivity of 30.7 W/m.K was obtained.