Tensile Elastic Modulus Research Articles

Analysis of the Influence of Fiber Orientations in Carbon Fiber Reinforced Composites on their Structural Properties Based on Eddy Current Measurements

Fiber-reinforced plastics (FRP) are a type of composite material consisting of a reinforcing structure and a plastic matrix. When compared to traditional construction materials, FRP has higher strength and stiffness due to the high mechanical properties of reinforcing fibers such as carbon or glass. However, the properties of FRP are dependent on the alignment of fibers within the composite, with deviations leading to reduced strength and stiffness. Eddy current testing is a non-destructive technique used to visualize carbon fibers in the composite and assess the impact of local fiber orientation on the structural properties of FRP. This study aims to understand the influence of local fiber orientation on tensile strength and elastic modulus by producing composites with defined fiber orientations, analyzing them with eddy current testing, and assessing their mechanical properties through tensile tests. The measured fiber orientations are then used to validate a finite element model, in which the actual, measured fiber orientation is applied to the simulation and correlated with the mechanical properties. In contrast to previous published studies measured fiber orientation is used, which as shown in this work, differs from the theoretically implemented fiber orientation.

Enhancing the physical properties of recycled low-density polyethylene and virgin low-density polyethylene blend using octanoate starch

Increasing global consumption of low-density polyethylene leads to more polymeric waste and challenges solid waste management. Therefore, the process of recycling or mixing recycled low-density polyethylene (RLDPE) with the same virgin low-density polyethylene (VLDPE) and enhancing the properties of this blend by adding different amounts of bioplastic such as Octanoate starch (OCST) is a good contribution to getting rid of plastic waste and obtaining new materials. This paper mixed the 20, 30 and 50 wt.% from RLDPE with VLDPE to determine the homogeneous blend. Also, 30, 40, and 50 wt. % from OCST were blended with homogeneous as a 20:80 RLDPE: VLDPE to obtain a new hybrid blend containing bioplastic. The scanning electron microscope (SEM) results showed the high surface roughness of the film RLDPE: VLDPE after adding the OCST. The tensile strength, elastic modulus, and hardness of the 20:80 RLDPE: VLDPE blend were 13.0 ± 1.467 MPa, 0.08 ± 0.016 MPa, and 42.3 ± 2.32 Shore A, while the tensile strength, elastic modulus, and hardness of the 12:48:40 RLDPE: VLDPE: OCST were 14.3 ± 1.626 MPa, 0.1 ± 0.032 MPa, and 50.1 ± 2.78 Shore A respectively. On the other hand, the Fourier-Transform Infrared (FTIR) indicated that the strong bands at 1746 cm−1, 2856 cm−1, and 2927 cm−1 indicated stretching deformation of the ester carbonyl group and the methyl and methylene groups of OCST with blend polymers, respectively. The thermal properties as melting point, heat energy consumption, and heat flow difference increased from 122.52 to 123.73°C, −389.41 to −144.43 (mJ), and −77.88 to −28.89 (J/g) when the OCST content increased from 20:80 RLDPE: VLDPE to 12:48:40 RLDPE: VLDPE: OCST. Thermal decomposition led to the formation of functional groups such as hydroxyl and carbonyl on LDPE baskets and an increase in the carbonyl index after adding OCST to the RLDPE: VLDPE blend. The best hybrid blend was 12:48:40 RLDPE: VLDPE: OCST.

Stiffening of double-shelled fullerene molecules under uniaxial strains

Onion-like fullerenes (OLFs) have spherical and tunable shell structures that make them perfect solid lubricants, but their molecular mechanical properties are largely unknown as they are extremely difficult to measure. In this computational study, double-shelled OLFs C60@C180, C80@C180, C60@C240 and C80@C240 are subject to uniaxial elastic strains to obtain their mechanical response. Compressive and tensile elastic moduli are calculated using density functional theory with van der Waals correction. We found that the tensile elastic moduli of the single- and double-shelled fullerenes are always larger than the compressive ones by about 50% to 100%. Inserting C80 into C180 causes an increase in compressive elastic modulus from 96.8 GPa to 178.6 GPa, while inserting C60 into C240 cause much smaller increases. The key factor that determines the stiffening effects is the relative sizes of the inner and outer shells.

Experimental research on mechanical, material, and metallurgical properties of Inconel 600: Application in elevated temperature environment

Experimental research on mechanical, material, and metallurgical properties of Inconel 600: Application in elevated temperature environment

Tensile anisotropy of powder bed fusion steel 316L: A practical study on the effect of build orientation

This study investigated the tensile anisotropy of steel 316L fabricated via laser powder bed fusion (L-PBF), built at different orientations. Tensile tests were performed on as-built L-PBF specimens produced at 0°, 15°, 30°, 45°, 60° and 90° angles. The yield strength, ultimate tensile strength and elasticity modulus experienced a decrease with an increasing build angle. Conversely, elongation at fracture increased as the build angle increased. The Elasticity modulus was found to be substantially lower than the nominal values reported in the material data sheet of the L-PBF equipment manufacturer. Fractography performed via Scanning Electron Microscopy (SEM) has found indications of porosity and lack of fusion that may have contributed to lower Elasticity modulus and an overall impacted mechanical performance. A complementary powder quality analysis has offered further insights on this and provided indications on the powder recycling impact.

Orthotropic mechanical properties of PLA materials fabricated by fused deposition modeling

Polylactic Acid (PLA) sample manufactured by fused deposition modeling (FDM) technique is typically assumed to be transversely isotropic without a thorough examination of its orthotropy in three-dimensional space. This study investigated the mechanical orthotropy of PLA samples with two air gap levels (0 mm and -0.05 mm) and various loading directions. Tensile strength and elastic modulus were experimentally measured and the Hill48 yield model and orthotropic elastic model were calibrated. Results revealed that the anisotropy induced by interlayer bond was more pronounced than that within layer. Introducing a -0.05 mm air gap remarkably reduced voids in printed samples, enhancing the stiffness and strength of tensile samples. It also delayed the transition of fracture modes in intra-layer samples as the filament angle increased from 0° to 90°, which shifted from filament breakage to combined fracture mode and subsequently to interface failure. Despite these improvements, the inherent anisotropy of FDM printed PLA materials remained due to the oriented molecular chains and insufficient chain diffusion. The study emphasizes the importance of orthotropic mechanical models, demonstrating their reliability through calibration with acceptable accuracy.

In vitro and in vivo evaluation of the osseointegration capacity of a polycarbonate-urethane zirconium-oxide composite material for application in a focal knee resurfacing implant.

Currently available focal knee resurfacing implants (FKRIs) are fully or partially composed of metals, which show a large disparity in elastic modulus relative to bone and cartilage tissue. Although titanium is known for its excellent osseointegration, the application in FKRIs can lead to potential stress-shielding and metal implants can cause degeneration of the opposing articulating cartilage due to the high resulting contact stresses. Furthermore, metal implants do not allow for follow-up using magnetic resonance imaging (MRI).To overcome the drawbacks of using metal based FKRIs, a biomimetic and MRI compatible bi-layered non-resorbable thermoplastic polycarbonate-urethane (PCU)-based FKRI was developed. The objective of this preclinical study was to evaluate the mechanical properties, biocompatibility and osteoconduction of a novel Bionate® 75D - zirconium oxide (B75D-ZrO2) composite material in vitro and the osseointegration of a B75D-ZrO2 composite stem PCU implant in a caprine animal model. The tensile strength and elastic modulus of the B75D-ZrO2 composite were characterized through in vitro mechanical tests under ambient and physiological conditions. In vitro biocompatibility and osteoconductivity were evaluated by exposing human mesenchymal stem cells to the B75D-ZrO2 composite and culturing the cells under osteogenic conditions. Cell activity and mineralization were assessed and compared to Bionate® 75D (B75D) and titanium disks. The in vivo osseointegration of implants containing a B75D-ZrO2 stem was compared to implants with a B75D stem and titanium stem in a caprine large animal model. After a follow-up of 6 months, bone histomorphometry was performed to assess the bone-to-implant contact area (BIC). Mechanical testing showed that the B75D-ZrO2 composite material possesses an elastic modulus in the range of the elastic modulus reported for trabecular bone. The B75D-ZrO2 composite material facilitated cell mediated mineralization to a comparable extent as titanium. A significantly higher bone-to-implant contact (BIC) score was observed in the B75D-ZrO2 implants compared to the B75D implants. The BIC of B75D-ZrO2 implants was not significantly different compared to titanium implants. A biocompatible B75D-ZrO2 composite approximating the elastic modulus of trabecular bone was developed by compounding B75D with zirconium oxide. In vivo evaluation showed an significant increase of osseointegration for B75D-ZrO2 composite stem implants compared to B75D polymer stem PCU implants. The osseointegration of B75D-ZrO2 composite stem PCU implants was not significantly different in comparison to analogous titanium stem metal implants.

Viability Study of Serra da Estrela Dog Wool to Produce Green Composites.

The environmental emergency has alerted consumers and industries to choose products derived from renewable sources over petroleum derivatives. Natural fibers of plant origin for reinforcing composite materials dominate the field of research aiming to replace synthetic fibers. The field of application of green dog wool composite materials needs to be reinforced and proven, as the industry is looking for more sustainable solutions and on the other hand this type of raw material (pet grooming waste) tends to grow. Hence, in the present work, the feasibility of applying natural fibers of dog origin (mainly composed by keratin) in green composites was studied. The green composites were developed using chemically treated dog wool of the breed Serra da Estrela (with NaOH and PVA) as reinforcement and a green epoxy resin as a matrix. The chemical treatments aimed to improve adhesion between fibers and matrix. The fibers' composition was determined using X-ray Diffraction (X-RD). Their morphology was determined using a scanning electron microscope (SEM). The wettability of the fiber was also evaluated qualitatively by analyzing drops of resin placed on the fibers treated with the different treatments. The mechanical properties of the composites were also studied through mechanical tensile, flexural, and relaxation tests. Overall, the best results were obtained for the dog wool fibers without treatment. The tensile and flexural strength of this biocomposite were 11 MPa and 26.8 MPa, respectively, while the tensile and flexural elastic modulus were 555 MPa and 1100 MPa, respectively. It was also possible to verify that the PVA treatment caused degradation of the fiber, resulting in a decrease in mechanical tensile strength of approximately 42.7%, 59.7% in flexural strength and approximately 59% of the stress after 120 min of relaxation when compared to fiber made from untreated dog wool. On the other hand, the NaOH treatment worked as a fiber wash process, removing waxes and fats naturally present on the fiber surface.

A novel fiber-reinforced polymer rope: Concept design and experimental evaluation

The present study proposes using a twisted rope with flexible fiber-reinforced polymers (FRPs) instead of wire rope and synthetic rope in environments requiring high load-bearing capacity and corrosion resistance. Resin toughening modification was conducted to manufacture flexible FRPs, and experimental evaluations were performed to assess the tensile and flexural properties of the impregnated fiber bundles (IFBs), as well as the tensile behaviors of the seven-IFB strands and the seven-strand ropes. The results demonstrated that the modified epoxy resin exhibited a decrease in both strength and elastic modulus, while its ductility was enhanced. Tensile and bending experiments confirmed that incorporating an additional 10% of Qishi toughener (QS-VA-3) was the optimal choice for producing low-modulus and high-toughness resins. Although the tensile properties of resin modified IFBs may show a slight reduction, their repeated bending behavior can be significantly improved. The tensile load-displacement curves of the FRP strand and rope displayed a linear increasing trend and experienced intermediate fracture failure, resembling that observed in IFBs. Furthermore, it was found that the tensile strength and elastic modulus of the strand decreased with an increase in lay length. The secondary twisting can enhance the tensile behavior of ropes compared to strands with equivalent lay lengths.

Limonene and its derived oligomer as bioactive additives in starch/coffee husks biocomposites for food packaging applications

In this study, antioxidant, and antimicrobial starch-based biocomposite films reinforced with coffee husks (S/CH) were developed by incorporating either limonene (LM) (S/CH/LM) or its oligomer derivative, poly(limonene) (PLM) (S/CH/PLM), at different concentrations (5–10 % w/w of starch). Through a comprehensive assessment of film properties, morphology, and structure, a comparative analysis between the two additives was proposed. Scanning electron microscopy (SEM) revealed some defects throughout the polymer matrix after additive incorporation. The tensile strength (TS) and modulus of elasticity (ME) showed a decrease upon the inclusion of both LM and PLM, while the elongation at break (E) increased. Notably, PLM exhibited outstanding antioxidant capacity, enhancing the films by 108 % over control samples. Additionally, at just 5 % concentration, PLM effectively inhibited the growth of Escherichia coli ATCC 11775 (35.33 ± 2.52 mm) and demonstrated an impressive UV–Vis barrier, comparable to the highest amount of LM incorporated. Therefore, this research highlights the potential of coffee husk-reinforced starch biocomposites with limonene-derived additives as a promising solution for food packaging applications. The comparative analysis sheds light on the advantages of using the PLM in terms of antioxidant and antimicrobial properties, contributing to the advancement of active packaging technologies.

The Effect of Eggshell Powder on the Properties of Purple Sweet Potato Starch/Eggshell Bioplastics

Petroleum-based plastics are derived from non-renewable sources and are supremely utilized in packaging industries due to their superior flexibility, mechanical and barrier properties. However, due to petroleum-based plastics do not degrading easily, researchers are turning into bioplastics. This study was conducted to examine the effect of eggshell powder (ESP) loadings on the physical and mechanical properties of purple sweet potato (PSP) starch bioplastics. PSP starch was extracted and mixed with glycerol as plasticizer and 0 – 40 % by weight of ESP to fabricate PSP/ ESP bioplastic using solution casting method. The incorporation of ESP in PSP starch matrix (in terms of functional groups and bonding existed) was analyzed by using Fourier Transform Infrared spectroscopy (FTIR-ATR). The physical property of PSP/ESP bioplastics is characterized through water absorption test. Whereas the mechanical properties (tensile strength, Young’s Modulus and elongation at break) of bioplastics was analyzed by tensile test. From FTIR analysis, it can be summarized that the PSP/ESP bioplastic was successfully synthesized. The tensile strength and modulus of this bioplastics increase from with the addition of ESP up to 20 wt.%. This is because further addition of ESP above 20 wt.% reduces tensile strength and modulus of elasticity of this bioplastic. In terms of elongation at break, a slight decrease in elongation at break as the ESP loadings increases. Similarly, the water absorption capacity of this bioplastic significantly decreases as the percentage of ESP increases. The incorporation of ESP into this bioplastic able to reduce rate of water absorption from 26.32 % to 12.5 % in 72 h. Therefore, these bioplastics exhibit good physical and mechanical properties that can be used as alternatives for synthetic plastic to cope with waste generation and disposal problems, especially in the food industry.

Research on manufacturing high-strength concrete and ultra-high-performance concrete from crushed sand in the Central Highlands, Southeast and Mekong Delta

Ultra-high-performance concrete (UHPC) is a new-generation concrete with superior features in terms of strength, durability, workability, and toughness, helping to improve the load-bearing capacity of structures. UHPC can ensure the sustainability of construction against corrosive impacts from the surrounding environment. The study was carried out on concrete aggregates based on the M3Q fine-grain aggregate, in which QS was replaced by crushed sand (CS) collected from different mines in the Central Highlands, Southeast, and the Mekong Delta. The test results provide a perspective on the compressive strength, flexural strength, direct tensile strength, elastic modulus, and Poisson's ratio of concrete with different types of CS. The results showed that high-strength concrete (HSC) and super-high-performance concrete can be made with the CS aggregates mentioned above. In particular, the compressive strength of concrete with aggregates of Fico CS and Hung Vuong CS can reach 124–130 MPa, while its bending tensile and direct strengths are over 15 MPa and 7 MPa, respectively.

Development of 3D Printing Filaments from Recycled PLA Reinforced with Nanoclay

This study focused on the development of 3D printing filaments suitable for fused deposition modeling (FDM) by recycling expired polylactic acid (PLA) filaments. The 3D printing filaments were processed into pellets by incorporating montmorillonite (MMT) nanoclay into the expired PLA filaments through twin-screw extrusion with varying concentrations of 1%, 3%, and 5 wt.%. These composite pellets were reprocessed to filaments through a filament extruder with a diameter of 1.75 mm. These filaments underwent different characterization techniques to test its mechanical and thermal properties. The thermal properties showed increasing values in the glass transition temperature, crystallization temperature, and melting temperature with a decrease in the specific heat upon incorporating increasing amount of MMT nanoclay. Furthermore, thermogravimetric analysis (TGA) showed a positive impact with better thermal stability when the MMT content was incorporated. In terms of mechanical properties, the study showed that the addition of 1 wt% MMT nanoclay, provided an increase in both the tensile strength and elastic modulus comparable to the virgin 3D printing PLA filament.

Effect of Nano-Alumina (Al<sub>2</sub>O<sub>3</sub>) Loading on the Thermo-Mechanical Properties of Poly(Lactic Acid) for Fused Deposition Modeling 3D Printing Applications

This research focused on the development of filament composite materials for fused deposition modeling (FDM) 3D printing applications. The main objective of this study was to fabricate and characterize poly (lactic acid) (PLA) filaments with varying amounts of alumina (Al2O3) nanopowder (0, 2.5, 5.0, and 10.0 wt.%). The resulting PLA/Al2O3 filament blends were produced using hot-melt extrusion. The filament blends were subjected to different characterization techniques and mechanical testing. The results indicate that the thermal stability of the filaments increased with increasing filler content. Furthermore, PLA with 5.0 wt.% nanoAl2O3 exhibited 55.84%, 66.14%, and 45.84% improvement in tensile strength, elastic modulus, and toughness, respectively.

A novel fiber‐reinforced polymer rope: Simulation and theoretical investigation

AbstractThe study proposed using twisted rope made of flexible fiber‐reinforced polymers (FRPs) instead of wire and synthetic ropes in high load‐bearing and corrosive environments. Finite element model verification and parameter analysis were conducted for the rope, along with deriving theoretical equations for its tensile properties. Increasing the lay length improved model accuracy, with a maximum bearing capacity within a 10% margin of error compared to experimental results. The model length had minimal impact on calculation results, while changes in radial mesh size (0.13 and 0.2 mm) and friction coefficient (0–0.2) greatly affected maximum contact stress. The tensile strength and elastic modulus of the strand remained almost constant (approximately 1142 MPa and 44 GPa) when the friction coefficient was altered. Increasing lay length (6D–20D) enhanced the tensile properties of the strand, whereas tendon diameter (1–3 mm) had negligible impact. Arranging inner and outer strands with the same lay length was better for circular ropes than those with the same lay angle. Inverse lay direction reduced rope torque and increased strand contact stress. Rectangular ropes had higher strength and modulus conversion efficiency, with lower contact stress compared to circular ones. The accuracy of rope equations improved with longer lay lengths, and adding a correction factor for lay length can modify the equation.Highlights A flexible FRP rope with high strength and twisted form was proposed. The effect of construction factors on the tensile behaviors of ropes was clarified. Equations for calculating the tensile properties of ropes were derived.

Α coherent optimization course of the silicon nitride nanofiller load in medical grade isotactic polypropylene for material extrusion additive manufacturing: Rheology, engineering response, and cost-effectiveness

By enabling the development of complex structures with adaptable qualities, techniques for additive manufacturing have opened new routes for material development and research. In this research, silicon nitride (Si3N4) ceramic nanoparticles are incorporated into polypropylene (PP) matrices. Various loading levels and standardized test specimens that adhere to ASTM criteria are created. The main goal is to thoroughly characterize these composites with an emphasis on their mechanical capabilities. The rheological, thermomechanical, and morphological properties of 3D-printed PP/Si3N4 composites created using material extrusion (MEX) 3D printing are examined. Thermogravimetric analysis and differential scanning calorimetry are exploited to study thermal stability and phase transitions in composite materials. Mechanical testing is conducted to determine mechanical qualities, such as flexural and tensile strength and modulus of elasticity. For detailed characterization of the nanocomposites, scanning electron microscopy, and Raman spectroscopy are also performed. The results provide insight into the impact of Si3N4 nanoparticles on the mechanical properties, thermal stability, and rheological behavior of PP/Si3N4 composites. The 2 wt% Si3N4 filler showed overall the best performance improvement (21% in the tensile modulus of elasticity, 15.7% in the flexural strength, and high values in the remaining properties assessed). The nanocomposite with the maximum Si3N4 loading of wt% showed a 33.6% increased microhardness than the pure PP thermoplastic, showing a promising wear resistance for the parts built with it. This research reveals the ability of Si3N4 ceramic nanoparticles to improve the mechanical characteristics of PP-based compounds produced by MEX 3D printing.Graphical

The Effects of Reusing Cobalt-Chromium Alloy Powder on Its Mechanical Properties and Grain Size: An In Vitro Study.

To characterize material changes that may occur in virgin cobalt-chromium (Co-Cr) alloy powder when it is blended with alloy powders that have been reused multiple times. Initially, 20 kg of virgin Co-Cr powder was loaded into a laser-sintering device. The tensile test specimens were fabricated in the first (Group 1), fourth (Group 2), seventh (Group 3), tenth (Group 4), and thirteenth (Group 5) production cycles (N = 15). Prior to fabricating the specimens, powder alloy samples were collected from the powder bed for analysis. The tensile strength, elastic modulus, and percent elongation were calculated with tensile testing. Scanning electron microscopy and energy dispersive x-ray spectroscopy (SEM/EDS) and laser particle size distribution (LPSD) were used to analyze the alloy powder samples. The fracture surface of one tensile test specimen from each group was examined via SEM/EDS. One-way ANOVA followed by Dunnett T3 test was used for statistical analysis (α = .05). No difference was observed between groups in terms of tensile strength. A statistically significant difference was observed between Groups 1 and 2 in terms of percent elongation. Groups 2 and 4 were statistically significantly different in terms of both elastic modulus and percent elongation (P ≤ .05). SEM images of the powder alloy showed noticeable differences with increasing numbers of cycles. SEM images and the EDS analysis of the fractured specimens were in accordance with the strength data. Reusing Co-Cr alloy powder increased the particle size distribution. However, there was no correlation between increased cycle number and the mechanical properties of the powder.

Core-shell nanofibers containing L-arginine stimulates angiogenesis and full thickness dermal wound repair

Despite the advances in medicine, wound healing is still challenging and piques the interest of biomedical engineers to design effective wound dressings using natural and artificial polymers. In present study, coaxial electrospinning was employed to fabricate core–shell nanofiber-based wound dressing, with core composed of polyacrylamide (PAAm) and shell comprising 0.5 % solution of L-Arginine (L-Arg) in aloe vera and keratin (AloKr). Aloe vera and keratin were added as natural polymers to promote angiogenesis, reduce inflammation, and provide antibacterial activity, whereas PAAm in core was used to improve the tensile properties of the wound dressing. Moreover, L-Arg was incorporated in shell to promote angiogenesis and collagen synthesis. The fiber diameter of PAAm/(AloKr/L-Arg) core–shell fibers was (93.33 ± 35.11 nm) with finer and straighter fibers and higher water holding capacity due to increased surface area to volume ratio. In terms of tensile properties, the PAAm/(AloKr/L-Arg) core–shell nanofibers with tensile strength and elastic modulus of 2.84 ± 0.27 MPa and 62.15 ± 5.32 MPa, respectively, showed the best mechanical performance compared to other nanofibers tested. Furthermore, PAAm/(AloKr/L-Arg) exhibited the highest L-Arg release (87.62 ± 3.02 %) and viability of L929 cells in vitro compared to other groups. In addition, the highest rate of in vivo full thickness wound healing was observed in PAAm/(AloKr/L-Arg) group compared to other groups. It significantly enhanced the angiogenesis, neovascularization, and cell proliferation. The prepared PAAm/(AloKr/L-Arg) core–shell nanofibrous dressing could be promising for full-thickness wound healing.

Effect of basalt fibers and silica fume on the mechanical properties, stress-strain behavior, and durability of alkali-activated slag-fly ash concrete

Previous investigations have shown that there is limited exploration into the combined mechanism of silica fume and basalt fibers of various lengths on the performance of alkali-activated concrete. Based on this, the primary focus of this study is to elucidate the current knowledge gaps concerning the mechanical properties and durability of basalt fiber-reinforced alkali-activated concrete, with a particular emphasis on its stress-strain behavior. The effects of basalt fiber content (i.e., 0.2%, 0.4%, and 0.6% Vf), basalt fiber length (i.e., 6 and 12 mm), mixing proportions of 6 mm and 12 mm basalt fibers (i.e., 75:25, 50:50, and 25:75) and silica fume content (i.e., 3%, 6%, and 9%) on the workability, mechanical properties, stress-strain behavior, and durability of alkali-activated concrete were investigated. Based on experimental results, predictive models were proposed for the splitting tensile strength, flexural tensile strength, elastic modulus, peak strain, and stress-strain relationship of basalt fiber-reinforced alkali-activated concrete, showing excellent predictive accuracy. Additionally, the durability properties of all samples, including shrinkage, carbonation depth, and chloride ion permeability, were also tested. The results indicate that the combined effect of fibers and silica fume can enhance the mechanical properties and durability of the concrete. Finally, the reinforcement mechanism of the synergistic action of fibers and silica fume is discussed.

Recycling of beryllium swarf for the preparation of Be/Al composites with high mechanical properties by pressure infiltration method

Utilizing recycled beryllium swarf and aluminum, Be/Al composites containing varying volume fractions of beryllium were fabricated via the pressure infiltration method, which realized the direct and green recycling of beryllium swarf without dust. This study systematically investigates the microstructure and mechanical properties of Be/Al composites. Under pressure infiltration conditions, the molten aluminum successfully repaired the defects in the beryllium swarf. Additionally, the serrated morphology of the swarf increased the contact area between the beryllium swarf and aluminum matrix, enhancing interfacial bonding strength. As the volume fraction of beryllium swarf increased, the tensile strength, yield strength, and elastic modulus of the composite material increased, while elongation exhibited a different trend. Considering the service conditions of the material, 60% volume fraction is the optimal parameter. The fracture of Be/Al composites comprised both ductile fracture of the Al phase and brittle fracture of the Be phase. The debonded surface of beryllium swarf reinforcement was generally smooth rather than densely cracked or large serrated.