Enhancement Of Mechanical Properties Research Articles

Understanding the impact of plasma functionalized MWCNTs on the structure, physicochemical and mechanical properties of PEMA

In this study, plasma functionalized multiwalled carbon nanotubes, f-MWCNTs, were incorporated into a poly(ethyl methacrylate), PEMA, polymer matrix at different wt.% (0.005, 0.01, and 0.02 wt.%) to prepare nanocomposite films using the traditional solution casting method. The XRD, Raman spectroscopy, XPS, TGA, mechanical analysis and UV–Vis spectroscopy techniques were employed to investigate the effects of the wt.% of f-MWCNTs on the structure, spectroscopic and other physiochemical properties of the synthesized films. XRD analysis showed a monotonic change in the PEMA structure upon incorporation of f-MWCNTs at different wt.%. The XPS results showed an increase of oxygen-based functional groups C-O and O-C-O on the PEMA/f-MWCNTs/ composite films compared to pure PEMA. Raman spectroscopy results consistent with the XRD and XPS findings, confirming the homogeneous distribution of f-MWCNTs in the PEMA matrix. Thermal stability of f-MWCNTs/PEMA improved as the f-MWCNTs content increased. Optical studies showed a reduction in the bandgap energy as the f-MWCNTs content increased, accompanied by significant improvements in optical properties such as refractive index (n), extinction coefficient (k), dielectric constants (ε′ and ε″), and optical conductivity (σopt). Mechanical testing revealed enhancements in breaking strength, Young’s modulus, yield stress, and elongation at break with increasing f-MWCNTs concentrations. Furthermore, the AC electrical conductivity of the films also improved, demonstrating better charge transport capabilities. These synergistic enhancements in optical, thermal, mechanical, and electrical properties make PEMA/f-MWCNTs nanocomposites promising candidates for advanced applications, including optoelectronic devices, optical components, and conductive packaging materials.

Simulation Study of the Water Ordering Effect of the β-(1,3)-Glucan Callose Biopolymer.

Callose, a polysaccharide closely related to cellulose, plays a crucial role in plant development and resistance to environmental stress. These functions are often attributed to the enhancement by callose of the mechanical properties of semiordered assemblies of cellulose nanofibers. A recent study, however, suggested that the enhancement of mechanical properties by callose might be due to its ability to order neighboring water molecules, resulting in the formation, up to room temperature, of solid-like water-callose domains. This hypothesis is tested by atomistic molecular dynamics simulations using ad hoc models consisting of callose and cellulose hydrogels. The simulation results, however, do not show significant crystallinity in the callose/water samples. Moreover, the computation of the Young's modulus gives nearly the same result in callose/water and in cellulose/water samples, leaving callose's ability to link cellulose nanofibers into networks as the most likely mechanism underlying the strengthening of the plant cell wall.

Development and Characterization of Milled Carbon Fiber-Reinforced Polypropylene Filaments for Fused Deposition Modeling: Mechanical Performance, Moisture Absorption, and Morphological Insights.

Abstract This study explores the production, characterization, and performance evaluation of carbon fiber-reinforced
polymer (CFRP) composite filaments designed for fused deposition modeling (FDM) applications. The primary
objective was to investigate the influence of milled carbon fiber (MCF) content on the mechanical, moisture
absorption, and morphological properties of polypropylene (PP)-based composites. Composite filaments were
produced by blending micro-sized MCFs with PP granules, followed by a two-step extrusion process to create
filaments with varying MCF contents (1–24 wt.%). Test specimens were fabricated using 3D printing to evaluate
the performance of the composite materials.
The results demonstrated a significant enhancement in mechanical properties compared to neat PP. The composite with 9.09 wt.% MCF achieved optimal performance, exhibiting increases in tensile and flexural strengths
by 74% and 99%, respectively, relative to neat PP. However, higher MCF contents (16 and 24 wt.%) led to
reduced mechanical properties due to insufficient fiber-matrix adhesion, resulting in fiber pull-out. Moisture absorption studies revealed that the inclusion of MCFs increased the water uptake of the composites, with higher
fiber concentrations correlating to greater moisture absorption.
These findings underline the potential of MCF-reinforced PP composites for applications requiring improved
mechanical performance, such as lightweight structural components. The study identifies an optimal fiber content
of 9.09 wt.% for maximizing strength while minimizing moisture-related trade-offs. Future efforts could focus
on enhancing fiber-matrix bonding to improve performance at higher fiber concentrations.

Effect of Powdered Nano-Local Banded Iron Formation (BIF) Rock on Some Mechanical Properties of Cementitious Concrete

Banded Iron Formation (BIF) rocks are a significant source of iron ore, and they can also be used in the production of cementitious materials. However, the BIFs of the Egyptian Eastern Desert (ED) are not currently employed in steel iron manufacturing due to their elevated silica content and the technical challenges and high cost associated with extracting iron ore from them. Furthermore, the incorporation of nano-sized particles of BIF into cementitious mortar may impart specific characteristics that could enhance mechanical strength and durability, or even contribute to sustainability. This study examines the impact of nano- and powder-based materials derived from locally sourced BIF rocks on the properties of cementitious concrete when used as partial replacements for Ordinary Portland Cement (OPC). A comprehensive evaluation was conducted on concrete mixtures with varying cement replacement ratios, 1, 2, 3, and 4%, to assess the impact on key mechanical properties at different curing ages, 7, 28, and 90 days. The concrete samples exhibited significant enhancements in mechanical properties at all curing periods. The 2% Nano-BIF replacement yielded the most notable increase. Furthermore, X-Ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) analysis demonstrated that the Interfacial Transition Zone (ITZ) between the cement paste and aggregates exhibited a robust compacted bond, indicating that local nano-BIFs have the potential to serve as an effective additive for enhancing the mechanical properties of cementitious concrete.

Lightweight Aluminum Joint Design: Enhancement of Mechanical Properties through Novel Inter-layer and Powder Additives in Friction Stir Welding

Lightweight Aluminum Joint Design: Enhancement of Mechanical Properties through Novel Inter-layer and Powder Additives in Friction Stir Welding

Enhancement of mechanical, tribological and corrosion properties of ta-C coatings through soft/hard multilayer structures

Enhancement of mechanical, tribological and corrosion properties of ta-C coatings through soft/hard multilayer structures

Strategic enhancement of CoCrFeMnNi high-entropy alloy mechanical properties through a high-strength nano-scale nitride layer without geometrical or tolerance constraints

Strategic enhancement of CoCrFeMnNi high-entropy alloy mechanical properties through a high-strength nano-scale nitride layer without geometrical or tolerance constraints

High-pressure infiltration fabrication of WC-based self-lubricating ceramics with synergistic enhancement of mechanical and lubrication properties

High-pressure infiltration fabrication of WC-based self-lubricating ceramics with synergistic enhancement of mechanical and lubrication properties

Nano-scale microstructural evolution and mechanical property enhancement mechanism during crack inhibition in nickel-based superalloys fabricated by laser powder bed fusion

Nano-scale microstructural evolution and mechanical property enhancement mechanism during crack inhibition in nickel-based superalloys fabricated by laser powder bed fusion

Mechanical and thermal property enhancement of silicon nitride-reinforced PLA composites for high-performance 3D printing applications

Mechanical and thermal property enhancement of silicon nitride-reinforced PLA composites for high-performance 3D printing applications

Experimental investigations of mechanical and water absorption behavior of basalt/jute bio composite

Abstract With the growing interest in eco-friendly composites, this study investigates the impact of stacking sequence on the mechanical properties, water absorption behavior, and fabrication quality of hybrid Basalt and Jute composites. Using the hand layup method, six stacking configurations were evaluated for tensile, flexural, impact, and hardness performance, along with water absorption under distilled water, saline water, and moist sand conditions. Results revealed significant enhancements in mechanical properties, with Basalt-Jute-Jute-Basalt (BJJB) achieving a 231% improvement in tensile strength compared to the Jute-Jute-Jute-Jute (JJJJ) baseline. The Jute-Basalt-Basalt-Jute (JBBJ) configuration exhibited the highest flexural strength of 166.6 MPa, while Basalt- Jute-Basalt-Jute (BJBJ) demonstrated superior resistance to moisture and the lowest void fraction (1.459%), indicative of high fabrication quality. SEM analysis identified fiber pullout, matrix cracking, and interfacial debonding as critical failure mechanisms. These findings highlight the potential of hybrid Basalt-Jute composites as cost-effective, high-performance materials suitable for lightweight and sustainable structural applications in automotive, marine, and construction industries.

Exploring bandgap tuning and vibration isolation performance of innovative negative stiffness metastructures

Negative stiffness metamaterials with tunable bandgap properties present promising applications in vibration control and mechanical property enhancement. This study proposes and compares two metastructures with unit cells exhibiting negative stiffness, achieved through the snap-through behavior of a top beam under displacement. The vibration isolation performance of these models is investigated through theoretical and finite element analyses, with experimental verification of transmission results. Both structures demonstrate significant band gaps, and mode shape analysis of the unit cells reveals the mechanisms underlying bandgap formation. A parametric study examines the effects on bandgap characteristics, including opening and closure, as well as transmission behavior in arrayed configurations. Results indicate that both metamaterial models, with their negative stiffness properties, can create multiple band gaps and achieve excellent vibration isolation, making them strong candidates for vibration isolation applications in engineering structures.

Mechanical property strengthening by post-heat treatments in NiTiCu shape memory alloys fabricated by twin-wire arc additive manufacturing

ABSTRACT To address the challenges of wide transformation hysteresis as well as the poor properties of NiTi-based alloys fabricated by twin-wire arc additive manufacturing, post-heat treatments were employed in as-deposited NiTiCu alloys. After aging at 450°C, 550°C, and 650°C, the alloys exhibited significant reduction in the precipitate sizes, narrow transformation hysteresis, uniform distribution of microhardness, and substantial improvement in mechanical properties. With the increase of the aging temperature, the matrix grain size and the precipitate size coarsened, which was detrimental to the resultant mechanical properties. The alloys aged at 450°C exhibited the narrowest transformation hysteresis of 11.7°C and optimal mechanical properties (tensile strength of 539 MPa and fracture strain of 6.9%). The enhancement of mechanical properties can be attributed to the smaller matrix grain size and precipitate size and the higher proportion of high-angle grain boundaries in this material condition. This work provides practical significance for the twin-wire arc additive manufacturing and performance optimisation of NiTi-based ternary alloys.

Welding speed effects in underwater and conventional friction stir welding of dissimilar aluminum alloy 6061-T6 and 5083-H12 joints

This study investigates the influence of welding speed on the mechanical and microstructural properties of dissimilar aluminum alloy joints (AA6061-T6 and AA5083-H12) joined using Underwater Friction Stir Welding (UFSW) and Conventional Friction Stir Welding (CFSW). The experiments were conducted at a constant tool rotation speed of 1120 rpm and varying welding speeds (20 to 80 mm/min). Results showed that UFSW achieved peak temperatures 13% lower than CFSW. Moreover, the generated peak welding temperature was inversely proportional to welding speed in UFSW and CFSW. Optimal performance was observed at 63 mm/min, where UFSW produced an 89% reduction in intermetallic compound (IMC) thickness and a 21% finer grain size compared to CFSW. Additionally, UFSW joints exhibited a 10.20% increase in tensile strength and a 7% increase in hardness over CFSW. The enhanced cooling effect in UFSW contributed to these improvements, yielding more uniform material flow, refined microstructure, and reduced IMC formation. These findings suggest UFSW as a superior technique for achieving high-quality dissimilar aluminum alloy joints, with significant enhancements in mechanical properties and microstructural refinement.

Enhanced Antibiotic Release and Mechanical Strength in UHMWPE Antibiotic Blends: The Role of Submicron Gentamicin Sulfate Particles.

Periprosthetic joint infections (PJIs) are a major complication of total joint replacement surgeries. This study investigated the enhancement of mechanical properties and antibiotic release in ultra-high molecular weight polyethylene (UHMWPE) through the encapsulation of submicron gentamicin sulfate (GS) particles, addressing the critical need for improved implant materials in orthopaedic surgery, particularly in managing PJIs. The present study involved embedding submicron GS particles into UHMWPE flakes at concentrations of 2% to 10% by weight. These particles were prepared and blended with UHMWPE flakes using a dual asymmetric centrifugal mixer, and the blends were consolidated. The present study compared the mechanical properties and antibiotic release rate of UHMWPE containing submicron, medium (as-received), and large (resolidified) GS particles. UHMWPE samples with submicron GS particles exhibited superior mechanical properties, including higher ultimate tensile and Izod impact strengths, compared with samples with larger particles. Additionally, the submicron GS UHMWPE blends demonstrated a markedly higher and more sustained antibiotic release rate. This study highlights the potential of incorporating submicron GS particles into UHMWPE to drastically improve the feasibility of using these therapeutic and functional spacer implants in expanded indications. By offering improved mechanical strength and effective, prolonged antibiotic release, this innovative material could be used as a spacer implant to reduce the considerably high morbidity and mortality associated with PJIs. This material has the potential to prevent PJIs not only in high-risk revision cases but also in primary total joint arthroplasty procedures.

Enhanced mechanical properties and in vitro bioactivity of silicon nitride ceramics with SiO2, Y2O3, and Al2O3 as sintering aids.

Silicon nitride (Si₃N₄) ceramics exhibit excellent mechanical properties and biocompatibility, making them highly suitable for biomedical applications, particularly in implants. In this study, the mechanical properties and bioactivity of Si₃N₄ ceramics with varying amounts of Y₂O₃-Al₂O₃-SiO₂ sintering aids were investigated. Increasing the sintering additive content from 4wt% to 8wt% substantially improved the bulk density of the ceramics, leading to notable enhancements in mechanical properties. These included a Vickers hardness increase to 10.07GPa, a flexural strength increase to 605MPa, and a fracture toughness increase to 2.43MPam1/2. The optimal combination of mechanical properties was achieved with 8wt% sintering additives due to the higher aspect ratio and lower porosity. After immersion in simulated body fluid (SBF), the surface of the Si₃N₄ ceramics was coated with a Ca and P-rich layer, morphologically similar to hydroxyapatite. The layer formation was facilitated by the presence of SiO₂, which promoted hydroxyapatite nucleation and growth, as well as the rapid release of Ca2⁺ ions and the sustained stability of the apatite layer.

Study of the modification mechanism and reinforcement performance of functionalized graphene-based structural adhesives

ABSTRACT This study investigates the effectiveness of modified graphene (MGE) for developing novel structural adhesives and their application in concrete beam reinforcement. The research aims to reveal the mechanism of MGE and evaluate the effect of different reinforcement methods on the flexural performance of concrete beams. Two adhesive formulations – original structural adhesive (OSA) and functionalized graphene-based structural adhesive (FGSA) – were examined alongside two reinforcement methods: the grouting reinforcement method and the adhesive fiber-reinforced polymer (FRP) method. The results show that the increased spacing of the functionalized MGE flakes improved their dispersion in epoxy resin, enhancing cohesive forces through bonding interactions and leading to the enhancement of the basic mechanical properties of FGSA by 6% to 12%. Compared to OSA, the application of FGSA improved the flexural properties of concrete beams, with the degree of improvement depending on the reinforcement method, while the failure mode of the beams remained unchanged. In addition, the FGSA/FRP combination showed the most significant improvement in the fracture parameters (220% to 480%) compared to the unreinforced control, highlighting its efficiency and cost-effectiveness as a reinforcement method. These findings offer valuable insights into reinforcement strategies for concrete beams, addressing the limitations of structural adhesive bond strength and optimizing reinforcement techniques.

Enhancement of mechanical properties of carbon fiber epoxy composites using methylmethacrylate-butadiene-styrene (MBS) core-shell nanoparticles

This work investigates the use of readily dispersed methylmethacrylate-butadiene-styrene (MBS) core-shell nanoparticles to improve the mechanical properties of carbon fiber epoxy (CF/EP) composites. Through the vacuum-assisted resin transfer molding (VARTM) process, CF/EP composites were manufactured with varying MBS particle loadings from 1 wt. to 7 wt. %. The mechanical properties of the composites were determined via three-point bending, Charpy impact, short-beam shear, and Mode-I fracture toughness tests, adhering to the relevant ASTM standards. The results show that the addition of MBS particles significantly increased Mode-I interlaminar fracture toughness (GIc), with the highest increase observed at 7 wt. % particle loading, demonstrating a nearly 177% improvement over the reference composite. The flexural modulus of composites slightly decreased with 1 wt. % MBS nanoparticles, indicating increased flexibility, while a synergistic effect at 7 wt. % MBS enhanced stiffness and structural reinforcement. The incorporation of MBS nanoparticles in CF/EP composites also enhanced Charpy impact strength and damping properties, with the highest impact strength observed at 7 wt. % MBS. Higher MBS content reduced the storage modulus, while the glass transition temperature remained relatively unchanged.

The Impact of Incorporating Silicon Dioxide Nanoparticle Fillers into Polymethyl Methacrylate Denture Base Material on Flexural Strength

Several previous studies have incorporated NPs-SiO2 at various concentration percentages in heat-cure PMMA to increase the mechanical properties of the denture base. Many researchers found out that adding NPs-SiO2 at low concentrations has shown enhancements in mechanical properties compared to higher concentrations percentages. This study was conducted to examine the impact of adding Silicon Dioxide as a nanoparticle filler at diver’s concentrations in heat-cured PMMA denture bases on flexural strength. Fifty specimens with dimensions (65 x 10 x 2.5 mm3) were fabricated from heat-cure-PMMA, and then specimens were divided into 5 groups according to different concentrations of NPs-SiO2. Each group consisted of 10 specimens. Moreover, 10 samples were prepared as a control group without any additives of NPs-SiO2 to PMMA. Three-point bending test was carried out using a universal testing machine to measure the flexural strength of specimens. Data analyses were conducted through analysis of variance and Tukey’s post hoc test (α = 0.05). The one-way ANOVA showed that there were statistically significant differences among groups (p<0.05). The highest flexural strength value was observed for the group (S1), with concentrations 0.5% by weight of NPs-SiO2 into PMMA. The control group showed a lower value of flexural strength than other groups. Low concentration percentages of NPs-SiO2 added to PMMA could increase the flexural strength of the PMMA denture base. According to the current investigation, 0.5% was the optimal concentration percentage for adding NPs-SiO2 to PMMA while maintaining an appropriate flexural strength value.

Multiscale analysis of the mechanical properties and interface damage mechanisms of carbon fiber reinforced polypropylene composites

AbstractIn this article, the mechanical properties of carbon fiber reinforced polypropylene (CF/PP) composites at different carbon fiber (CF) mass fractions were systematically investigated. A comprehensive examination is provided through the integration of experimental testing, numerical simulation, and theoretical analysis, revealing the enhancement effects of CF on the polypropylene (PP) matrix across multiple scales. Experimental results demonstrated that the incorporation of CF significantly impedes crack propagation and enhances the fracture resistance of the composites. Specifically, at a CF mass fraction of 15%, the elastic modulus of the composites is enhanced by 21.7% compared with pure PP, while the tensile strength increases by 40.9%–43.2%. The addition of maleic anhydride grafted polypropylene (MAH‐g‐PP) as a compatibilizer significantly improves the interfacial compatibility between CF/PP. Furthermore, finite element simulations revealed the damage evolution process at the CF/PP interface during tensile loading. Based on the Mori‐Tanaka model, the elastic modulus was predicted, aligning well with experimental and simulated results. This research offers a scientific basis for the design and application of CF/PP composites and contributes to the advancement of high‐performance composites.Highlights CF/PP composites show enhancements in mechanical properties with CF addition MAH improves interfacial adhesion between CF and PP, boosting tensile strength Multiscale experimental and FEA studies reveal CF/PP interface damage mechanisms Mori‐Tanaka model accurately predicts the elastic modulus of CF/PP composites