Lightweight Structural Materials Research Articles

Discussion on Human-induced Vibration of Glulam Pedestrian Arch Bridge

In the process of urban modernization, with the wide application of lightweight and high-strength structural materials and the constant pursuit of structural aesthetics, footbridges tend to develop in the direction of long span, slender and gentle. However, the problem of human-induced vibration comfort caused by such bridges is becoming increasingly prominent. Especially the wooden footbridge, although its static performance (such as bearing capacity and deflection) can well meet the structural design and use standards, its dynamic performance, especially the excessive vibration under the excitation of crowds, has become the core consideration to control the design of modern wooden footbridges.

A novel cobweb-like sub-grain structured Al-Cu-Mg alloy with high strength-plasticity synergy

Al-Cu-Mg alloys, as the most widely used lightweight structural materials, have been recognized as promising candidates in the transportation field for a low-carbon economy. However, the tensile strength and plasticity of alloys cannot be simultaneously improved to satisfy the requirements of continuously upgraded transportation vehicles. In this work, inspired by high-tensile strength and high plasticity of cobweb structure, a novel cobweb-like sub-grain structure was developed in Al-Cu-Mg alloys by a successive solution, high-strain-rate rolling (4.4 s-1), cryogenic treatment (–196°C) and aging process (SRCA). Notably, the tensile strength and plasticity of this alloy were superior to those reported in the current study. An ultrahigh Vickers hardness and tensile strength value of 206.2 Hv and 619.6 MPa, which were 39.8% and 31.8% higher than those of traditional T6 heat-treated Al-Cu-Mg alloys, were obtained after SRCA. Meanwhile, an increase in the elongation of this alloy from 4.31% to 8.23% (increase of 90.9%) was also achieved. More importantly, the high strength-plasticity (“double high”) Al-Cu-Mg alloy was attributed to a cobweb-like sub-grain structure, which was proposed for the first time by utilizing reverse thinking to enhance plasticity through elevating dislocations, due to the formation of high-density dislocations from high-strain-rate rolling and rearrangement effect of dislocations from cryogenic treatment. Furthermore, the strength-plasticity mechanism was verified using in-situ tensile electron back scatter diffraction (EBSD), molecular dynamics (MD) simulations, and crystal plasticity (CP) models. The results indicated that the cobweb-like sub-grain structure, resembling countless walls, formed barriers that hindered dislocation migration towards high-angle grain boundaries (HAGBs) and absorbed them, thereby reducing the occurrence of stress concentration zones, i.e., the dislocation absorption and stress-strain sharing mechanisms. Additionally, the strengthening mechanism was associated with synergistic strengthening by multiscale microstructures, including micron-sized grains, micron-sized high-density dislocation lattices, and nanosized Al2CuMg phases, which were activated by successive deformation processes. Consequently, the concept of biomimetic structure design, which may serve as an effective method for achieving structural materials with high strength-plasticity synergy, can be extended to transportation fields, such as railway tracks and body structure design.

Achieving metallurgical bonding in steel faceplate/aluminum foam sandwich via hot pressing and foaming processes: interfacial microstructure evolution and tensile behavior

This study introduces an innovative approach to fabricating aluminum foam sandwich with aluminized steel faceplates through metallurgical bonding. The process involves the use of foamable precursor, prepared via melt stirring, and subsequent hot pressing and foaming, offering a cost-effective and industrially feasible method for producing lightweight structural materials and connection of steel/aluminum dissimilar metals. This study focuses on exploring the changes in the microstructure of the bonding interface before and after foaming, and revealing the impact of these changes on the tensile results. Foaming experiment shows that foamable sandwiches have superior foaming ability, and the core layer density after foaming is between 0.283 and 0.591 g/cm ³. Microstructural characterization results demonstrate that, during the hot pressing process, fine equiaxed grains are observed on the iron side of the interface, indicating dynamic recrystallization occurred. The formation of a small amount of η-Al5Fe2 at the interface is a primary factor causing the deflection of the fracture path. Subsequently, during the foaming process, intermetallic compounds (IMCs) θ-Al13Fe4, τ5-Al7Fe2Si, and β-Al4.5FeSi formed sequentially, mainly determined by the diffusion reaction of silicon elements. The formation of these IMCs led to an increase in microhardness at the interface and a decrease in shear strength. Digital image correlation was utilized to examine strain distribution under tensile loading. The result indicates that the damage accumulation is characterized by the formation and expansion of strain bands, with failure manifested as the interconnection of these strain bands.

The effect of post heat treatment on microstructural evolution and mechanical properties of Ti2AlNb intermetallic alloy prepared by point-forging and laser-deposition

Ti2AlNb-based intermetallic alloy is considered to be the latest class of light-weight structural material severing in the range of 600∼750 °C. Hybrid interlayer point-forging with laser-deposition (PF-LD) provides a new idea to produce near-net-shape Ti2AlNb part with promising mechanical performance. The present work mainly investigated the effect of post heat-treatment on microstructural evolution and tensile mechanical properties of PF-LDed Ti2AlNb alloy. The experimental results demonstrated that solution-treated at 940 °C–1020 °C followed by aging at 840 °C was effective to regulate phase morphology and tensile mechanical properties. With the consecutive increase of solution temperature, more fine-lamellar O-phase was reprecipitated within parent B2/β matrix during secondary aging treatment. The ultimate tensile strength was enhanced significantly from 1055.5 MPa to 1148.1 MPa with the help of precipitation hardening effect. In the meantime, stronger stress accumulation introduced by fine-lamella also exerted a detrimental impact on tensile strain capability, and the elongation after failure decreased from 10.9 % to 7.4 % with increasing solution temperature. Considering above results, this study provides a basic research for exploring the heat treatment of PF-LDed Ti2AlNb-alloy, and it is feasible to obtain high-strength and high-ductility properties by tailoring phase morphology.

Enhancement of the compressive performances of additive manufactured Corrax maraging stainless steel lattice by heat treatment

The objective of this study was to investigate the influences of integrated solution and aging treatment (SAT) on the compressive properties of laser powder bed fusion (LPBF) Corrax maraging stainless steel lattices. Cubic and face-centered cubic with Z-axis strut (FCCZ) lattices were produced and used to formulate two types of functionally-graded material (FGM) lattices. The lattices with FGM directions parallel and vertical to the stress were designated as FGM-P and FGM-V lattices, respectively. The compressive performances and fracture mechanisms were identified experimentally by digital image correction and theoretically by finite element analysis.The results show that SAT can significantly increase the specific strengths of these lattices by 34–42 %. The compressive performances and fracture mode of the FGM-V sample principally corresponded to the rule of mixture. However, the FGM-P sample did not follow the rule of mixture because its deformation concentrated only in the cubic-dominated regions. Moreover, the SEAs of the cubic and FGM-P samples were respectively improved by 30 % and 19 % by SAT, given their higher compressive strength and stable stress–strain curve. SAT can be applied to further extend the future application of these materials as cost-effective, high-performance lightweight structural materials.

Sound absorption performance of honeycomb metamaterials Inspired by Mortise-and-Tenon structures

To address the limitations of traditional honeycomb sandwich structures in attenuating mid to low-frequency sounds, particularly in configurations with minimal thickness and weight, this study introduces an innovative honeycomb acoustic metamaterial incorporating the traditional Chinese mortise-and-tenon joint. We systematically investigate the acoustic absorption characteristics of the modified honeycomb structure through theoretical analysis, empirical validation, and numerical simulations. Our experimental setup maintained consistent geometric parameters across all trials and demonstrated that the resonance frequency of the modified honeycomb structure decreased by 10 % relative to its conventional counterpart. We conducted detailed analyses on the influence of micropore positioning, tenon geometric dimensions, and micropore diameters on the acoustic performance. Notably, elongating the tenon from 2 mm to 6 mm resulted in a 15 % reduction in resonance frequency, whereas increasing the micropore-to-tenon distance from 0 mm to 4 mm led to a 30 % increase. The integration of the mortise-and-tenon joint significantly enhances the mid to low-frequency sound absorption performance of the honeycomb panels. This improvement is achieved while preserving the structural benefits of low panel thickness and shallow cavity depth, alongside simplified processing of micropores. Our findings elucidate a promising approach to augmenting the acoustic properties of lightweight structural materials, thereby extending their application potential in noise control engineering. This study not only contributes a novel perspective to the design and optimization of acoustic metamaterials but also highlights the potential for integrating traditional architectural techniques with modern material science to enhance noise control solutions.

SiO2 decorated wood nanocomposite with enhanced mechanical performance, flame and water resistance

Development of lightweight and strong structural material using fast-growing poplar wood is promising for green and sustainable engineering. Herein, the overall performances of fast-growing natural poplar wood (NPW) are significantly enhanced via delignification, in situ growth of SiO2 followed by densification. The SiO2/compressed-delignified-wood (SiO2/CDW) nanocomposite obtained exhibits outstanding mechanical properties including a bending strength of 395.6 ​MPa, a tensile strength of 253.4 ​MPa, and a toughness of 7.1 ​MJ/m3, which is improved by 1548 ​%, 240 ​% and 590 ​%, respectively compared with NPW. In addition, the ignition time and burning time of SiO2/CDW nanocomposite are prolonged by 700 ​% and 112 ​% compared to those of NPW. Moreover, the specific wear rate of SiO2/CDW is 18 ​× ​10−6 mm3/Nm, which is 72.6 ​% lower than that of NPW. Moreover, the spring-back ratios of SiO2/CDW in 95 ​% and in water are 45.2 ​% and 66.7 ​%, which are lower than those of CDW (64.6 ​% and 92.4 ​%). The SiO2/CDW nanocomposite with enhanced mechanical, flame/water retardant and wear performances are promising to meet the needs of modern engineering as green and sustainable materials.

Effect of Fatigue and Precorrosion Fatigue on Fatigue Crack Propagation and Fracture Failure Behavior of 5B70 Aluminum Alloy

Aluminum alloys are ideal lightweight structural materials for spacecraft, but they are susceptible to local corrosion during service. Herein, a systematic investigation is carried out to determine the fatigue behavior of 5B70 aluminum alloy under salt spray precorrosion. The mechanism of salt spray corrosion, fatigue life, crack propagation, and failure fracture mechanism of 5B70 aluminum alloy are studied. Under the salt spray corrosion, 5B70 aluminum alloy mainly undergoes pitting corrosion via a galvanic corrosion mechanism. After precorrosion, the formation of macroscopic fatigue cracks is accelerated, which significantly reduces its fatigue life. Fracture occurs due to single crack initiation and propagation under fatigue conditions. The fatigue crack tip undergoes a mixture of intergranular and transgranular modes, but mainly transgranular mode. Multiple strain localization phenomena occur during precorrosion fatigue, and corrosion pits on the surface provide a tortuous crack propagation path; the fatigue crack tip is mainly transgranular mode.

An interfacial interlocking strategy for upcycling wool textiles to prepare polypropylene composite via interfacial diffusion and assembly

Substantial waste of wool textiles, along with a lack of effective treatment technology, has resulted in a significant resource and environmental constraints. Integrating wasted wool textiles with polymer is an effective way to prepare lightweight structural materials, but the resulting properties is closely linked to the interfacial interaction. Here, we proposed an interfacial manipulation strategy to direct interfacial diffusion and aggregation of amide-based nucleating agents (WBG) in polypropylene (PP)/wool fiber (WF) composites. Accordingly, the branched WBG fibers were anchored onto the WF surface to construct an interlocking interface between WF and PP so as to strengthen the interfacial interaction. The formation and regulation mechanism of the branched WBG fibers were demonstrated. Benefited from mechanical interlocking and β-nucleating function of the branched WBG fibers, the interfacial interaction between the WF and PP matrix was enhanced while the formation numerous β-PP was cultivated, endowing the composite with excellent strength and ductility. To demonstrate the application potential of this strategy, waste wool textiles were alternately embedded between WBG-containing PP sheets to create an interlocking interfacial laminate with an exceptional combination of strength and toughness, which is important to upcycle waste wool textiles.

Development of solid-state hybrid capacitor using carbon nanotube film as current collector

Structural energy-storage devices are receiving considerable attention because they can simultaneously store electrical energy and provide structural support, thereby offering high volumetric and gravimetric capacities. Although carbon fiber–based materials have been the most popular choice for current collectors, their conductivity and specific surface area are relatively low; this limits the ability to load other active materials on to the current collector. Carbon nanotube (CNT) fiber is a promising alternative for lightweight structural materials because it has a density of less than 1 g cm−3 as well as high strength and electrical conductivity. In this study, we produced a light, strong, and porous CNT film (CNTF) via direct spinning for use as a current collector. The CNTF exhibited a high specific strength compared with Al foil. We also created an activated carbon–lithium titanium oxide hybrid capacitor with the CNTF current collector, which achieved a capacity similar to that of a capacitor having an Al current collector. Furthermore, a planar pouch cell created using a solid polymer electrolyte achieved a capacity of 74.1 mAh g−1, which is comparable to that of coin cells. Thus, our findings highlight the feasibility of CNTF as a material for current collectors and provide a foundation to develop manufacturing processes for structural batteries.

Development of optimum performance model during spark-eroded processing of rheocasted Al6061/Cenosphere MMCs

ABSTRACT In the present study, an improved wettability casting route was used to prepare lightweight structural materials. Using the compo casting process, an Al6061 alloy was created with cenosphere particles at various weight percentages (2, 4, 6, and 8 wt%). The molten aluminium slurry incorporated hollow alumina silicate particulates. X-ray diffraction (XRD) analysis of the aluminium matrix composites (AMCs) confirmed the presence of cenospheres without any intermetallic components. Further processing of the metal matrix composites (MMCs) was conducted using electric discharge machining (EDM) with a circular copper electrode. The EDM process parameters were controlled to measure response variables such as material removal rate (MRR), tool wear rate (TWR), and surface roughness (SR). The effects of different combinations of machining parameters – including pulse current, pulse-on time, reinforcement percentage, and flushing pressure – on these performance characteristics were observed. Experimental trials were designed using the face-centred central composite design (CCD) of the response surface methodology (RSM). Optimal process variable conditions led to significant improvements in surface finish. Additionally, an artificial neural network (ANN) model was used to determine the best conditions for EDM processing. The ANN model demonstrated a strong correlation coefficient of 0.99 between the predicted and experimental values of MRR, TWR, and SR.

Recent approaches of interface strengthening in fibre metal laminates: Processes, measurements, properties and numerical analysis

Recently, there is a pressing need for high-performance and lightweight structural materials in aircraft and automobile industry; fibre metal laminates (FMLs) are suggested ideal candidates for aviation industry. FMLs are hybrid composite material comprised of thin-metal sheets and fibre-reinforced polymers (FRPs). By combining the features of both components, FMLs possess high tolerance to fatigue damage, exceptional impact resistance and an outstanding weight-to-strength ratio. However, maintaining high structure integrity of FML layers – without debonding – remains the primary challenge in FMLs-based structures. The present review explores the recent developments in manufacturing techniques and surface treatments aimed at enhancing the interfacial strength between FML layers. Recently, adding nanofillers into FRPs and FMLs is gaining attention. These nanofillers can enhance mechanical performance of FRPs/FMLs, strengthen the interface in FMLs; and add functionalities such as gas and water impermeability. The article discusses the recent studies on employing nanofillers in FMLs and adhesively bonded structures; and their (nanofillers) role in enhancing the crack resistance of FMLs. It also explores failure mechanisms in FMLs through experimental methods and advanced numerical simulations. A comprehensive review of the existing studies assists in understanding the complex failure mechanisms, aiming to find optimal input conditions that yield desired mechanical performance. Furthermore, the article introduces machine learning techniques in adhesively bonded structures and potential application in FMLs-related research. The article concludes with perspectives on the limitations, current challenges, and future prospects for FMLs and nanofiller-reinforced FMLs.

A transparent, strong, moldable wood laminated composite as a sustainable decorative building material

Delignified wood (DW) retaining its microstructure has increasingly been used as an alternative to synthetic or natural fibers in the preparation of fiber-reinforced composites for novel light-transmitting, high-strength structural materials. In this study, wood laminated composite (WLC) was prepared by impregnating with cycloaliphatic epoxy resin (CAE) and laminating using DW as a continuous reinforcing fiber. Results showed that DW effectively strengthened the resin matrix, increasing the epoxy resin's strength by 25.44 %, while CAE modified the wood's opacity, achieving a transmittance of up to 74.83 %. The mechanical and optical properties of the WLC can be effectively tuned through various lamination combinations. Additionally, due to the UV curing properties of CAE and its infiltration of DW, uncured WLC had long-term shade storage capability and excellent processability. The WLC developed in this study combines good processing, mechanical, and optical properties, making it an attractive option for sustainable home decoration and lightweight structural materials.

Buckling resistance of ultra-low-density carbon fiber curved-wall honeycomb based on stretching process

Although honeycomb is a kind of lightweight structural material with great potential, its specific strength is not always able to meet the requirements, especially in the weight-sensitive field. Inspired by the bionic idea of cuttlebone, the curved-wall configuration design is proposed to strengthen the buckling impedance of honeycomb, which can effectively prevent the premature occurrence of buckling failure mode induced by thin walls. Compared with the straight-wall honeycomb materials of the same geometric size, the probability of buckling failure in curved-wall honeycomb materials proposed in this paper is reduced by more than 22 %. Moreover, to achieve the preparation of curved-wall configuration, a processing strategy that uses stretching process to prepare ultralight carbon fiber honeycomb (Carbcomb) material is firstly introduced. Compared to the Hexcel Corporation’s aluminum honeycomb with a density of 21 kg/m3, for the Carbcomb, the specific compressive strength and specific shear strength along both the L and W directions respectively improved by 57 %, 61 % and 77 %. In addition, the minimum density of fabricated Carbcomb (14.6 kg/m3) is less than that of the Hexcel's products (16 kg/m3), and the research findings fill the gap of the carbon fiber honeycomb material in low density areas (10 ∼ 30 kg/m3). More importantly, this process which does not require much manual operation can effectively avoid the problems of unstable mechanical properties, difficult mass production and high preparation cost of the existing carbon fiber structural parts. This curved-wall configuration design and fabricated approach widens the potential of carbon fiber honeycomb as a structural material, and makes it possible for lower cost and higher efficiency in aerospace and transportation applications.

Potentials of Polyacrylonitrile Substitution by Lignin for Continuous Manufactured Lignin/Polyacrylonitrile-Blend-Based Carbon Fibers

While carbon fibers (CFs) are still the most attractive reinforcement material for lightweight structures, they are mostly manufactured using crude oil-based process chains. To achieve a higher eco-efficiency, the partial substitution of polyacrylonitrile (PAN) by renewable materials, such as lignin, is investigated. So far, this investigation has only been carried out for batch manufacturing studies, neglecting the transfer and validation to continuous CF manufacturing. Therefore, this work is the first to investigate the possibility of partial substituting lignin for PAN in a continuous process. Lignin/PAN-blended CFs with up to 15 wt.-% lignin were able to attain mechanical properties comparable to unmodified PAN-based carbon fibers, achieving tensile strengths of up to 2466 MPa and a Young’s Modulus of 200 Pa. In summary, this study provides the basis for continuous Lignin/PAN-blended CF manufacturing.

A biogenic geodesic dome of the silica skeleton in Phaeodaria

Unique architectures of microbial skeletons are viewed as a model for the architectural design of artificial structural materials. In particular, the specific geometric arrangement of a spherical skeleton 0.5–1.5 mm in diameter of shell-bearing protists, Phaeodaria (Aulosphaera sp.), is remarkably interesting because of its similarity to a geodesic polyhedron, which is a hollow framework with 6-branched nodes that requires minimal building material for maximal strength. A phaeodarian skeleton composed of silica rods 5–10 µm in diameter was characterized as a distorted dome that is based on an icosahedron sectioned with a 7-frequency subdivision. The major difference of the biogenic architecture from the ideal geodesic dome is the coexistence of 7- and 5-branched nodes with the distortion of the frames and the presence of radial spines. From a microscopic perspective, the frames and radial spines were revealed to be hollow tubes having inner fibers and lamellar walls consisting of silica nanoparticles 4–8 nm in diameter with interlayer organic matter. The high degradability of the silica skeleton in seawater after cell mortality is ascribed to the specific nanometric composite structure. The biological architectonics sheds light on the production of environmentally friendly, lightweight structural materials and microdevices.

Comprehensive Study on the Properties of AZ91/x-Si3N4 Composites for Their Prospective Application

Metal alloy matrix composites are generally lightweight structural materials with a high strength-to-weight ratio. They can be extensively used in various fields of modern engineering applications, such as aerospace and automotive components and biomedical engineering. This study focuses on the development and characterization of lightweight metal alloy matrix composites for industrial applications, with a particular emphasis on magnesium (Mg) alloys as a replacement for aluminum-based alloys. Mg alloys offer significant weight advantages, being 33% lighter than aluminum and 75% lighter than steel, making them highly desirable for use in various engineering fields. In the present study, Mg (AZ91) alloy reinforced with x-Si3N4 composites (x = 0, 1, 3, 5, 7, 9 wt.%) were fabricated using a liquid state process. The AZ91/x-Si3N4 composites were evaluated through physical, mechanical, wear, and microstructural characterization. The experimental results, supported by statistical analysis, demonstrated that the incorporation of Si3N4 particles amplified the mechanical properties, wear resistance, and porosity of the composites. However, the presence of the reinforced particles resulted in reduced forgeability and elongation, limiting certain deformation characteristics. The existence of the reinforced particles within the composites was confirmed through SEM analysis, providing visual evidence of their distribution and interaction within the Mg alloy matrix. Finally, it was concluded that the implication of the study could be sought for the light structural parts of aerospace, automotive, biomedical, and prosthetic applications.

Enhancing the adiabatic shear resistance of Ti-Zr-Nb-Al high entropy alloy via metastability engineering

Dual-phase Ti-Zr based high entropy alloys are lightweight structural materials with high specific strength, which are promising for the application in warheads and munitions. However, they usually experience adiabatic shear under impact, resulting in early failure. Here, we demonstrate an effective method to enhance the adiabatic shear resistance, benefiting from the transformation-induced plasticity (TRIP) effect. The composition of Ti-Zr-Nb-Al is designed based on a combination of lattice distortion enthalpy, mixing enthalpy, and Bo¯-Md¯ criteria, to enable a metastable solution structure. The alloy is directly water quenched from 900 ℃ to maximally keep the metastable BCC phase (MA), while an annealed alloy with the BCC+HCP dual-phase structure (PA) is also fabricated for comparison. The metastable MA alloy exhibits a doubled fracture strain and 79 % enhancement of impact energy compared with the dual-phase PA alloy, while its dynamic ultimate strength remains almost unchanged. Microstructural analyses at different dynamic stain levels reveal a BCC-α" phase transformation in MA alloy, which delays the generation of phase boundaries, avoids the premature stress concentration, and thereby delays the occurrence of adiabatic shear.

Corrosion behaviour of SiC particulate reinforced AZ31 magnesium matrix composite in 3.5 % NaCl with and without heat treatment

Magnesium is a lightweight structural material widely utilised in automotive applications. To enhance its mechanical properties, ceramic particulate reinforcement can be incorporated, particularly for wear resistance and high-temperature applications. However, the addition of ceramic particles to magnesium can compromise its corrosion resistance due to microgalvanic cell formation at the interfaces between the Mg matrix and the second phase. This reduces the chemical protection provided by the passive film. In this study, the corrosion properties of AZ31 and AZ31-5SiC samples were investigated, with a focus on the effect of heat treatment. Detailed microstructural and electrochemical analyses revealed that the AZ31 cast sample forms an effective passive film, resulting in improved corrosion resistance. However, the addition of SiC particles to AZ31 increased the corrosion rate, with corrosion mechanisms evolving over time. To mitigate these effects, a heat treatment process was employed to dissolve β-Mg17Al12 eutectic and Al8Mn5 intermetallic phases. The heat-treated AZ31 with SiC exhibited an improvement in corrosion resistance. These findings highlight the potential for heat treatment to enhance their corrosion resistance, thereby broadening their application prospects.

Superstrong and tough silk fibers cross-linked with functionalized graphene

Natural silkworm silks with an intriguing integration of good strength, modulus, toughness and biocompatibility, have been widely used in textile and medical industry. However, the strength of silkworm silks is inferior to that of spider dragline silks, which are the strongest natural silks but extremely low yield. Herein, we develop a feasible strategy to continuously produce superstrong and tough regenerated silk fibers (RSFs) through the reconstruction of hierarchical and cross-linked architectures. Amine functionalized graphene (NH2-G) has been introduced to improve the content of β-sheet and crystalline orientation, and glutaraldehyde (GA) has been used to bridge NH2-G and silk micro/nanofibrils (SNFs) to form a highly interconnected and closely packed network, resulting in the remarkably improvement of mechanical properties. The resultant fibers exhibit an excellent tensile strength of 1029.6 ± 144.8 MPa, a Young's modulus of 16.8 ± 1.5 GPa, and a toughness of 277.4 ± 17.0 MJ/m3, exceeding those of the natural silkworm silks, spider dragline silks and most other previously reported regenerated silk fibers. We believe that the high-performance silk-based fibers are promising applications in lightweight and advanced structural materials.