Enhanced Fracture Toughness Research Articles

High-quality multi-walled carbon nanotubes toughened glass-ceramic by a two-dimension carbon nanotube film interlayer

The brittleness of bioglass/ceramics limits their applications in bone repair. The toughness of the glass matrix can be enhanced by adding nanoscale reinforcements at random; however, the effect is quite limited. This study proposes a novel strategy to prepare controllable fabricating lamellar precursors with multiwalled carbon nanotubes (MWCNTs) film/glass/MWCNTs film sandwich structure by a high-temperature foaming method. Subsequently, the precursor was sintered by spark plasma to obtain a composite material with strong cross-linking between MWCNTs and the glass matrix. The mechanical properties of the composites were characterized, and mechanisms were analyzed by the finite element method. The results revealed that the glass composite with 1.0 wt% MWCNTs had a significantly enhanced fracture toughness (2.65 MPa m1/2) and flexural strength (145 MPa), which were 2.1 times and 1.8 times higher than those of pure glass, respectively. This increase in toughness is attributed to the strong resistance of the well-combined bent and entangled MWCNTs to the fiber pull-out process. The glass/MWCNTs composite showed a low electrical resistivity of 5.8 Ω cm, which would aid skeletal restoration. Thus, this strategy paves a facile way to prepare the highly toughed bio-glass with multifunctional properties.

Superhard bulk high-entropy carbides with enhanced toughness via metastable in-situ particles

Despite the extremely high hardness of recently proposed high-entropy carbides (HECs), the low fracture toughness limits their applications in harsh mechanical environment. Here, we introduce a metastability engineering strategy to achieve superhard HECs with enhanced toughness via in-situ metastable particles. This is realized by developing a (WTaNbZrTi)C HEC showing a solid solution matrix with uniformly dispersed in-situ tetragonal and monoclinic ZrO2 particles. Apart from a high hardness of 21.0 GPa, the HEC can obtain an enhanced fracture toughness of 5.89 MPa·m1/2, significantly exceeding the value predicted by rule of mixture and that of other reported HECs. The toughening effect is primarily attributed to the transformation of the metastable tetragonal ZrO2 particles under mechanical loading, which promotes crack tip shielding mechanisms including crack deflection, crack bridging and crack branching. The work demonstrates the concept of using in-situ metastable particles for toughening bulk high-entropy ceramics by taking advantage of their compositional flexibility.

High-pressure sintering of full-dense B6O ceramic with excellent hardness and fracture toughness

B6O is an extremely prospective hard material for industrial applications. Herein, the densification behavior, microstructure and mechanical properties of high-pressure sintered B6O ceramics at 6 GPa are investigated. The sintered B6O ceramics exhibit enhanced densification as the sintering temperature increases, and the ceramic sintered at 1700 °C possesses nearly full-dense characteristics with strong bonding at grain boundaries and exhibits outstanding mechanical properties (HV: 38.5 ± 0.7 GPa, HN: 45.7 ± 0.8 GPa, KIc: avg. 4.8 MPa·m1/2). At higher temperatures, however, the increase in sublimation pressure is counterproductive to densification. The enhanced fracture toughness of the full-dense B6O ceramics is mainly attributed to the high strength grain boundaries and the abundance of defects within the grains, which generate substantial crack bridging, crack deflection and grain pull-out.

Synergistic Reinforcement of Si3N4 Based Ceramics Fabricated via Multiphase Strengthening under Low Temperature and Short Holding Time.

Si3N4 ceramic as a tool material shows promising application prospects in high-speed machining fields; however, the required high mechanical properties and low-cost preparation of Si3N4 ceramic tool materials restrict its application. Herein, synergistic reinforced Si3N4 ceramic tool materials were fabricated by adding β-Si3N4 seeds, inexpensive Si3N4 whiskers and TiC particles into coarse commercial Si3N4 powder (D50 = 1.5 μm), then sintering by hot-pressing with low temperature and short holding time (1600 °C-30 min-40 MPa). The phase assemblage, microstructure evolution and toughening mechanisms were investigated. The results reveal that the sintered Si3N4 ceramics with synergistic reinforcement, compared to those with individual reinforcement, present an enhancement in relative density (from 94.92% to 97.15%), flexural strength (from 467.56 ± 36.48 to 809.10 ± 45.59 MPa), and fracture toughness (from 8.38 ± 0.19 to 10.67 ± 0.16 MPa·m1/2), as well as a fine Vickers hardness of 16.86 ± 0.19 GPa. Additionally, the various reinforcement modes of Si3N4 ceramics including intergranular fracture, crack deflection, crack bridging and whiskers extraction were observed in crack propagation, arising from the contributions of the added β-Si3N4 seeds, Si3N4 whiskers and TiC particles. This work is expected to serve as a reference for the production of ceramic cutting tools.

Investigation of Spark Plasma Sintering on Microstructure-Properties of Zirconia Reinforced Fluormica Glass for Dental Restorations.

Conventional sintering methods of dental ceramics have limitations of high temperature and slow cooling rates with requirements of additional heat treatment for crystallization. Spark plasma sintering (SPS) is an emerging technique that has the potential to process dental restorations with dense microstructures and tailor-made clinically relevant properties with optimized processing parameters. This study explored the potential of the SPS of zirconia-reinforced fluormica glass (FM) for dental restorative materials. FM glass frit was obtained through the melt-quench technique (44.5 SiO2-16.7 Al2O3-9.5 K2O-14.5 MgO-8.5 B2O3-6.3 F (wt.%)). The glass frit was ball-milled with 20 wt.% of 3 mol% yttria-stabilized zirconia (FMZ) for enhanced fracture toughness. The mixtures were SPS sintered at a pressure of 50 MPa and a heating rate of 100 °C/min for 5 min with an increase in temperature from 650-750 °C-850 °C-950 °C. Phase analysis was carried out using XRD and microstructural characterization with SEM. Micro-hardness, nano-indentation, porosity, density, indentation fracture toughness, and genotoxicity were assessed. The increase in the SPS temperature of FMZ influenced its microstructure and resulted in reduced porosity, improved density, and optimal mechanical properties with the absence of genotoxicity on human gingival fibroblast cells.

Coordination complexes as substitutes for metallic powders in ceramic-matrix-composites manufactured by aqueous colloidal processing: Enhanced fracture toughness and quantitative microstructure analysis

In fabrication of metal-reinforced ceramics, metallic powders are used as one of the raw materials, however, they hinder obtaining nanometallic particles in the matrix. The use of metallic nanopowders is inefficient, because they are highly flammable and require special storage and handling conditions (cool, dry inert gas, tightly sealed). Replacing metallic powders with coordination complexes allows to obtain nanocomposites in harmless manufacturing processes. The use of coordination complex of molybdenum (molybdenyl acetylacetonate) allowed to fabricate ZrO2/Mo composites by slip casting and gelcasting. The increase in fracture toughness (ca. 25%) was observed with the little concentration of the metallic phase (up to 1.5 wt%) in a composite. It results from gaining fine metallic particles (ca. 62 nm) in the ceramic matrix. SEM analysis revealed that crack propagation is inhibited by nano-sized metallic particles according to three mechanisms: crack deflection, crack blocking by plastic deformation and interface debonding.

Effect of laser focus shift on the forming quality, microstructure and mechanical properties of additively manufactured Al2O3–ZrO2 eutectic ceramics

Melt-grown Al2O3–ZrO2 eutectic ceramics have attracted extensive attention for harsh environment applications. In this work, Al2O3–ZrO2 eutectic ceramic is additively manufactured via one-step laser powder bed fusion (LPBF). The effect of laser focus shift on the relative density, phase formation, microstructure evolution, and mechanical properties was systematically investigated. The as-fabricated specimens are dominated by α-Al2O3 and t-ZrO2. The m-ZrO2 phase increases with increasing the laser defocus shift. The cellular-like structure formed when convection dominated at focal plane, while colony eutectic structure occurred when eutectic growth dominated at higher defocus shift. The deformation of cellular-like structure and needle-like ZrO2 into concave cells and dendritic structures is principally determined by the evolution of solid/liquid (S/L) interfaces. With the formation of needle-like or dendritic ZrO2 ductile phase, the crack propagation is prevented, leading to progressively enhanced fracture toughness with a maximum value of 8.04 MPa m1/2.

Role of scanning speed on the microstructure and mechanical properties of additively manufactured Al2O3‒ZrO2

AbstractMelt‐grown Al2O3–ZrO2 eutectic (AZ eutectic) ceramics have attracted extensive attention for harsh environment applications. In this work, AZ eutectic ceramic is additively manufactured via one‐step laser powder bed fusion (LPBF). The role of scanning speed on phase formation, crystallographic characteristics, microstructure evolution, and mechanical properties were systematically investigated. The as‐fabricated specimens are mainly composed of α‐Al2O3 and t‐ZrO2. Lower scanning speeds induced the formation of cellular structures consisting of randomly oriented ZrO2. In contrast, nanometer eutectic lamellar structure with well‐defined multiple crystallographic orientation relationships, for example, {100} Al2O3 || {100} ZrO2 and {0001} Al2O3 || {001} ZrO2, occurred at higher scanning speeds. Both the cell size and lamellar spacing decreased with increasing scanning speed. With the microstructure refinement, the crack propagation mode changes from intergranular to transgranular fracture, leading to progressively enhanced fracture toughness with a maximum value of 7.76 MPa·m1/2. The present work could shed light on tailoring the microstructure of LPBF AZ eutectic ceramic via varying processing parameters.

Dendrite microstructure formation and enhanced toughness in high‐entropy REAlO3–RE2Zr2O7 eutectic oxide

AbstractIn this study, complex GdAlO3–Gd2Zr2O7 and high‐entropy REAlO3–RE2Zr2O7 (RE = Nd, Sm, Gd, Eu, and Dy) composites with an equiaxed dendrite structure at eutectic composition are successfully fabricated using a gas levitation containerless solidification method. The unique microstructure of the composites is characterized, and the evolution process of the dendritic structure is explained. The formation of dendrites at eutectic composition is attributed to the rapid cooling induced by the shutoff of lasers and the homogeneous temperature field and nucleation achieved through gas levitation. The GdAlO3–Gd2Zr2O7 and high‐entropy oxide composites exhibit enhanced fracture toughness compared to the bulk samples fabricated by solid‐state sintering methods. The fracture toughness increases by 44% for GdAlO3–Gd2Zr2O7 bulk sample and 34% for high‐entropy REAlO3–RE2Zr2O7 bulk sample, which can be attributed to the complicated interfaces introduced by the equiaxed dendritic microstructure and the high thermal mismatch stress between two phases. Additionally, the high‐entropy REAlO3–RE2Zr2O7 oxides exhibit excellent high‐temperature stability, with no significant change in dendritic microstructure or fracture toughness even after holding at 1573 K for 100 h. These findings suggest the potential of high‐entropy eutectic oxide ceramics with dendrite microstructure for advanced engineering applications.

Experimental evaluation on the synergistic effect of PC/ABS/DGEBA blend in fracture toughness enhancement of CFRP composites at cryogenic temperatures

AbstractThe current study confirms that modified carbon fiber reinforced polymer (CFRP) composites have higher fracture toughness than unmodified CFRP composites achieved by exploiting the synergistic effect of a polycarbonate (PC)/acrylonitrile butadiene styrene (ABS) blend in toughening the diglycidyl ether of bisphenol A (DGEBA) epoxy resin. The CFRP composite specimens are tested at near cryogenic temperatures using TMA, DMA, and microcrack analysis to determine the best‐suited concentration of ABS in the PC/ABS blend. TMA and DMA results, as well as microcrack analysis at cryogenic temperatures (CT), confirm that the blend 90/10 is effective in reducing the brittle nature of DGEBA resin and increasing bond strength, resulting in the fracture toughness enhancement of CFRP specimens at CT. Further investigation of 90/10 modified CFRP (90/10 m‐CFRP) and unmodified CFRP specimens using Mode II fracture using ENF test and SEM analysis reveal significant reduction in brittle characteristics of matrix with increase in elongation at failure and fracture surface morphologies confirm nano web‐like structures bridging the CF layers, proving to improve fiber/matrix bond strength. This study concludes the effectiveness of hybrid PC/ABS blend in synergistically‐modifying DGEBA resin for improved fracture toughness of CFRP laminates across a wide temperature range (−150°C to 150°C).

Unraveling the superlattice effect for hexagonal transition metal diboride coatings

Superlattice structures enable the simultaneous enhancement in hardness (H) and fracture toughness (KIC) of ceramic-like coatings. While a deeper understanding of this effect has been gained for fcc-structured transition metal nitrides (TMN), hardly any knowledge is available for hexagonal diborides (TMB2). Here we show that superlattices can—similarly to nitrides—increase the hardness and toughness of diboride films. For this purpose, we deposited TiB2/WB2 and TiB2/ZrB2 superlattices with different bilayer periods (Λ) by non-reactive sputtering. Nanoindentation and in-situ microcantilever bending tests yield a distinct H peak for the TiB2/WB2 system (45.5 ± 1.3 GPa for Λ = 6 nm) but no increase in KIC related to a difference in shear moduli (112 GPa). Contrary, the TiB2/ZrB2 system shows no peak in H, but for KIC with 3.70 ± 0.26 MPa∙m1/2 at Λ = 4 nm originating from differences in lattice spacing (0.14 Å), hence causing coherent stresses retarding crack growth.

Rapid tempering of a medium-carbon martensitic steel: In-depth exploration of the microstructure – mechanical property evolution

Rapid tempering is a remarkable sustainable and energy-efficient way to modify properties of as-quenched martensite, particularly its toughness and ductility. In this work, tensile and fracture toughness properties, and microstructural evolution of a medium-carbon (0.4 wt%), low-alloy steel under different rapid tempering circumstances are discussed. The hot-rolled and direct-quenched specimens were subjected to rapid tempering treatments (heating rate of about 90 °C/s) to the different tempering temperatures (320–720 °C). As a reference material, one sample was subjected to conventional tempering at 420 °C for one hour. The results indicated that the mechanical properties and microstructural features are influenced considerably by tempering temperature rather than the holding time. Despite the short tempering duration, the strength of tempered martensite dropped (from a max. tensile strength of ∼ 2100 MPa to a min. of ∼ 1100 MPa) while ductility increased with increasing tempering temperature (from a tensile elongation of 4% to ∼ 15%). However, the rapidly tempered sample at 420 °C experienced a loss of fracture toughness as a result of coarse stick-like cementite precipitation. Microstructural observations revealed that, even with a short time frame, tempering temperature plays a significant role in the resulting cementite morphology. At lower tempering temperatures, the cementite precipitates have a stick-like structure, while at higher temperatures, they become more globular/spheroid-like. This change in cementite morphology led to an enhancement in fracture toughness. Overall, the results indicated that, by a proper design of the rapid tempering process, an excellent combination of tensile properties and fracture toughness can be obtained compared to conventional tempering while significantly saving time and energy.

Bioinspired fracture toughness enhancement of a fully bio-based epoxy resin

In this work, the concept of fracture toughness improvement via spatial variation of mechanical properties is applied to a composite with 100% bio-based carbon content based on epoxidized linseed oil. By proper selection of the hardener, either citric acid or sebacic acid, the mechanical properties were adjusted in a way that a bio-composite exhibits a stiff-soft-stiff layer architecture. Samples with two different thicknesses of soft interlayer (approx. 0.1 mm and 1.3 mm) were subsequently analyzed regarding their final performance. Specimen characteristics, owing to the curing and manufacturing process, were analyzed by means of local Fourier-transform infrared spectroscopy and differential scanning calorimetry. Fracture mechanics tests were performed to verify if the soft interlayer acts as a crack arrester. The results propose a high chemical compatibility between the used epoxy resins. Embedding a soft thin interlayer into a stiff resin matrix led to an increase in fracture toughness of 13 times, compared to the pure stiff resin. An increase in interlayer thickness led to a further increase in fracture toughness of 24 times. However, the stiffness decreased by 44% and 67%, respectively.

Toughening the additively manufactured Al alloys via manipulating microstructural heterogeneity

Achieving high strength and simultaneously high toughness of Al alloys remains challenging. Recent studies show that structural heterogeneity derived from additive manufacturing process is effective to improve mechanical properties of Al alloys. In this paper, the elaborately designed Al alloys with compositions of Al-Fe-Cu-xZr (x = 0.6, 0.8 and 1.3 at %) are subjected to laser powder bed fusion (LPBF). It is found that all three alloys show obvious heterogeneous structures with two distinct zones, i.e., coarse grain zones (CGZs) and fine grain zones (FGZs), where the FGZs have significantly higher hardness than the CGZs do. The grain size in both CGZs and FGZs decreases with increasing Zr content, and causes significant variation of mechanical properties. The Al-Fe-Cu-0.8Zr alloy exhibits the best combination of high yield strength and plasticity as well as the high resistance to crack propagation (corresponding to high fracture toughness). The enhancement of fracture toughness is mainly attributed to a sharp difference in local hardness at the interfaces between FGZs and CGZs. This work provides a promising strategy for toughening the additively manufactured Al alloys.

Inorganically Connecting Colloidal Nanocrystals Significantly Improves Mechanical Properties.

Understanding and characterizing the mechanical behavior of colloidal nanocrystal (NC) assemblies are important for developing nanocrystalline materials with exceptional mechanical properties for robust electronic, thermoelectric, photovoltaic, and optoelectronic devices. However, the limited ranges of Young's modulus, hardness, and fracture toughness (≲1-10 GPa, ≲50-500 MPa, and ≲10-50 kPa m1/2, respectively) in as-synthesized NC assemblies present challenges for their mechanical stability and therefore their practical applications. In this work, we demonstrate using a combination of nanoindentation measurements and coarse-grained modeling that the mechanical response of assemblies of as-synthesized NCs is governed by the van der Waals interactions of the organic surface ligands. More importantly, we report tremendous ∼60× enhancements in Young's modulus and hardness and an ∼80× enhancement in fracture toughness of CdSe NC assemblies through a simple inorganic Sn2S64- ligand exchange process. Moreover, our observation of softening in nanocrystalline materials with decreasing CdSe NC diameter is consistent with atomistic simulations.

Mechanical behavior and slag corrosion resistance of ZrSiO4/SiC reinforced MgO-C refractories

This investigation proposes a novel solution to enhance the thermal shock and slag corrosion resistance of low-carbon MgO-C refractories by integrating yttria-stabilized zirconium silicate (YSZS) and silicon carbide (SiC) powders in them. The results of this study revealed that incorporating YSZS and SiC particles in low-carbon MgO-C refractories improved the overall qualities of the refractories synergistically and increased the thermal shock resistance (TSR) from 11 cycles (for MgO) to 18 and 15 cycles, respectively, owing to their lower coefficients of thermal expansion (CTE) compared to magnesite. The addition of YSZS caused the cold compressive strength (CCR) of the MgO-C refractories to increase from 450 to 480 kg/cm2. The mechanical properties of the refractories were elevated as a result of fracture toughness enhancement and crack propagation within and between grains on the fracture surface. CaZrO3, Mg2SiO4, and MgSiO3 phases developed in the grain boundaries and served as corrosion-resistant materials, thereby resulting in reduced porosity and pore closure. Additionally, the TSR of the reinforced bricks was significantly improved due to their low CTE as compared to MgO, while slag resistance enhancement was caused by the formation of the CaZrO3, Mg2SiO4, and MgSiO3 phases.

Synergistic enhancement of strength, ductility, and toughness in a low carbon micro-alloy steel with an ultrafine-grained heterogeneous lamellar structure

Structural materials with heterostructure design have emerged as an efficient strategy to address the dilemma of balancing strength and ductility/toughness, resulting in increased interest from the scientific community. In this study, a novel ultrafine-grained heterogeneous lamellar (HL) structure has been architected in a common low-carbon micro-alloyed steel. The heterostructured steel exhibits a lamellar microstructure comprising alternating ultrafine/nano-grained lamellae and micrometer-grained lamellae, with a texture gradient along the thickness. Results show that the HL structure has a tensile strength comparable to quenched and tempered martensite (QTM) steel while retaining similar ductility as coarse-grained dual-phase (CG) steel. Furthermore, the HL specimen exhibits enhanced fracture toughness (KQ = 232.8 MPa m1/2), which is 11.3% and 28.8% higher than that in the CG and QTM specimens, respectively. Extrinsically, the macroscopical heterogeneous lamellar structure and microscopical elongated grain shape in ultrafine/nano-grained lamellae could provide substantial lamellar grain boundaries to hinder the connection of voids and make the crack propagation path more tortuous, which effectively increases the energy release rate to contribute to the exceptional fracture toughness. Intrinsically, not only micrometer-sized CG lamellae with high plastic deformation tolerance capacity can develop coarse (deep) dimples for energy consumption, but also the elongated ultrafine martensite grains can undergo significant plastic deformation together with the coordinated deformation of coarse-grained ferrite. We hope the strategy in this study may provide insights for microstructure optimization and synergistic strength-plasticity/toughness enhancement of conventional low-carbon micro-alloyed steels for structural applications.

Amorphous biomineral-reinforced hydrogels with dramatically enhanced toughness for strain sensing

Ionic conductive hydrogels are promising candidates for flexible wearable strain sensors and artificial skin. However, achieving high mechanical and sensing performance concurrently remains challenging. Herein, a novel biomineral-reinforced hydrogel composed of polyacrylamide (PAM) and highly stable amorphous calcium carbonate (ACC) is reported. Benefiting from the dual ionic doping strategy (Mg2+ and PO43−), ACC nanoparticles in hybrid hydrogels show a super stable amorphous nature. The resulting mineral hydrogel displays a high stretchability (>1150% strain), a dramatically enhanced fracture toughness (9.57±1.28 vs. 0.91±0.12 kJ m−2), and a desirable linear strain sensitivity. Moreover, the novel mineral hydrogel exhibits high biocompatibility and flame retardance, making it an appealing candidate for wearable device applications.

Unveiling thereinforcement potentiality of MWCNTs architecture towards the improvement of microstructural vis-a-vis mechanical and thermo-mechanical properties of pressureless sintered MgAl2O4 spinel ceramic composite

The study presented in this work focuses on the preparation of composites made of multi-walled carbon nanotubes (MWCNTs) and magnesium aluminate spinel through a pressureless sintering technique. The effects of sintering temperature and MWCNTs content on the densification behavior and mechanical properties of the composite were investigated in detail. The results revealed that the composite exhibited improved densification behavior, enhanced mechanical performance and decent control at the microstructural refinement with increasing MWCNTs content up to 0.75 wt%. The superior mechanical properties obtained in case of sintered composite were attributed to the synergetic toughening mechanisms involving the fiber pull out, cracks bridging and cracks deflection effects of reinforcing phases, observed as a resultant effect of strong interfaces with the matrix phase. The crystalline structural arrangement obtained from the XRD and Raman spectral analysis of the composites structure also satisfies the attainment of the promising reinforcement potential of the nanotubular structure. Most importantly, the study also exemplified the subsidiary interference of a surface decorative coating on the MWCNTs structure with the MgAl-binary oxide network. The strategic grafting of the oxide protective shell and the consequent development of a robust interfacial bridging network between the matrix and reinforcement phase regulated the energy dissipation characteristic for fiber debonding. This, in turn, restricted the crack growth phenomenon during mechanical loading, and thereby ultimately contributing to the enhanced fracture toughness, reduced thermal expansion co-efficient and augmented thermo-mechanical performance of the evolved spinel-based composite structure

Design of lightweight and antioxidant SiCnws/SiC(Mox, rGO) nanocomposite from molybdenum-modified precursors for aerospace vehicle components

Making lightweight SiC composite ceramics with good load-bearing and remarkable surficial antioxidant capacity for use in thermal protection system is challenging. In this contribution, an ingenious strategy is reported to produce SiC(Mox, rGO) nanocomposite polymer-derived ceramics (PDCs) for the first time by reactively re-pyrolyzing flexible polymolybdenumcarbosilane-vinyltriethoxysilane-graphene oxide (PMVG)/rigid SiC(Mox, rGO)p fillers blends. Highly cross-linked PMVG precursors connect up to five polycarbosilane (PCS) to optimize their formability. In-situ formed MoSi2 and Mo4.8Si3C0.6, compatible with β-SiC/SiOxCy/Cfree(rGO) matrix, can effectively strengthen interface bonding, promote nailing cracks, and even hinder β-SiC grain growth. More interestingly, using in-situ SiC nanowires (SiCnws) by Mo-containing catalyst to decorate samples is an efficient route to reinforce the ceramic network, and SiCnws/SiC(Mo0.1, rGO) nanocomposite PDCs display optimal Vickers hardness (5.19 GPa), enhanced fracture toughness (4.26 MPa·m1/2), high compressive strength (151.73 MPa), and low linear shrinkage (4.75%). Such products remain stability/integrity under flame scouring, their surface is covered by a dense SiO2 passivation layer with good self-healing capacity owing to unique non-destructive oxides of embedded MoSi2/Mo4.8Si3C0.6. This work can further provide a feasible way to overcome the critical fabrication process in lightweight porous PDCs with well-balanced high load-bearing and good thermal insulation integration for aerospace vehicle components.