Enhancement Of Strength Research Articles

A high-performance TRIP Mg-Sc-Zn alloy enhanced by fine grain strengthening and nano-precipitate strengthening

The Mg–Sc alloys have attracted considerable attention from researchers due to their martensitic transformation behavior. However, the relatively low yield strength limits their practical application. Thus, Zn alloying combined with annealing treatment was used to improve the mechanical properties by modulating its microstructure. Zn alloying can effectively delay the recrystallization rate and refine the grain size of the alloy. The β/α intensity ratio and grain size of β phase increase with the increasing annealing temperature. When the annealing temperature is 600 °C, the major phase is β-Mg-Sc with minor α-Mg-Sc, ScZn and Mg3Sc phases. Further increasing the temperature to 650 °C would lead to the dissolution of ScZn and Mg3Sc phases into the matrix, resulting in smaller precipitations. The Mg-Sc-Zn alloy annealed at 600 °C for 60 min owns the best comprehensive mechanical properties, with yield strength, ultimate tensile strength, and elongation of 307.2 MPa, 330.5 MPa, and 21.1%, respectively. Further TEM analysis reveals that fine grain reinforcement, precipitation reinforcement, and stress-induced martensitic transformation during tensile deformation are the main factors for the enhancement of strength and ductility in this alloy.

Enhancing clay soil reinforcement using the MICP-BIN method with biochar-induced nucleation

The microbially induced carbonate precipitation (MICP) method has gained extensive use in the realm of soil stabilization. The combination of MICP with biochar offers potential benefits in terms of simultaneous strength enhancement and vegetation cover enhancement. This study presents a novel microbial solidification technique known as the biochar-induced nucleation (MICP-BIN) method for reinforcing clay soil. Corn stover biochar was employed as an auxiliary material, mixed with dry clay powder, and subsequently reinforced using the MICP technique. Direct shear tests (DSTs), drying experiments, X-ray diffraction (XRD), and scanning electron microscopy (SEM) were also conducted to investigate the efficacy of the MICP-BIN method. Compared with that of the remolded soil, the shear strength of the treated soil exhibited a substantial increase of 22.4%, the CaCO3 content increased by 30%, and the shear strength improved by 389.5%. Similarly, the internal friction angle exhibited increases of 22.7% and 405.2%, while the cohesion showed improvements of 9.4% and 344.3%, respectively. The MICP-BIN method is found to increase suction for a given water content. Further, biochar amended soil possesses highest water retention ability (especially at lower suction magnitude) followed by MICP amended soil, MICP-BIN amended soil and untreated soil. The difference in water retention abilities among various soils is negligible at higher suction magnitude. Further, there is no significant change in air entry value of MICP-BIN amended soil as compared to the untreated soil and MICP amended soil. This study demonstrated the promising results achieved by combining biochar and the MICP-BIN technique, providing a novel approach for reinforcing soft ground.

La drives the remarkable strength enhancement of the Cu-Cr-Zr alloy through traditional thermo-mechanical treatment

The Cu-1Cr-0.1Zr alloy with different La addition (0 %, 0.07 % and 0.14 wt%) was processed using industry suitable two-step cold rolling and aging treatment to achieve superior strength and electrical conductivity. The role of La addition on the microstructure evolution and comprehensive properties of the Cu-1Cr-0.1Zr alloy is investigated during the second rolling and subsequent aging stages. During pre-aging process, the presence of La in the Cu-1Cr-0.1Zr-0.07La alloy led to formation of smaller precipitate sizes compared to La-free Cu-1Cr-0.1Zr alloy. This facilitates a stronger cut interaction between dislocations and precipitates during secondary rolling process, which promotes the redissolution of precipitates into Cu matrix and thus results in a larger decline of 44.72 % ICAS for the electrical conductivity of Cu-1Cr-0.1Zr-0.07La alloy. After post-aging treatment, precipitates are newly formed with increased number and refined size of Cr precipitates with maintaining a coherent relationship with the matrix. Besides, the addition of La promotes Cr-rich phase precipitation and dislocation accumulation. Resultantly, remarkable increase in tensile strength by 11 % with the addition of 0.07wt%La. While, the 0.14La added alloy exhibits comprehensive properties of tensile strength 600 MPa and electrical conductivity 80.08 %IACS after aging at 440 °C for 180 min. The increase in strength was primarily attributed to precipitation strengthening and dislocation strengthening. This work provides new kinds of Cu-1Cr-0.1Zr alloy and industrial suitable thermo-mechanical treatment for fabricating high performance cooper alloy sheets.

Strength formation mechanism and composition design of fly-ash and carbide-slag-stabilized mine solid waste road base

To achieve effective utilization of large-scale solid waste, this study prepared subgrade materials using mine waste, fly ash, and carbide slag as raw materials. The effects of the basic structure and composition ratio of the three raw materials on the performance of the subgrade materials were investigated. The mechanisms and strength enhancement effects of fly ash, carbide slag, and fly ash–carbide slag composite-stabilized mine solid waste were analyzed. The optimal mixing ratio of the subgrade materials was determined. When the mass ratio of carbide slag to fly ash was 1:4 and the total addition amount was 20%, the subgrade material had an optimal moisture content of 16.8%, maximum dry density of 1.70 g/cm3, and 90-day compressive strength of 8.51 MPa. This fully solid waste inorganic binder-stabilized subgrade material can effectively utilize large quantities of solid waste and meet the performance requirements of subgrade materials, thereby providing a good technical solution for large-scale solid waste disposal.

Three-dimensional mesoscale analysis of the dynamic tensile behavior of concrete with heterogeneous mesostructure

This paper investigates the dynamic tensile behavior of concrete under high strain rates. An optimized random concrete mesostructure generation procedure is established using the 3D entrance block (3D E(A, B)) algorithm to account for the intrinsic material heterogeneity. This approach avoids repetitive and complicated polyhedral aggregate overlapping checks in traditional methods, resulting in a highly efficient aggregate packing process. The nucleation, propagation, and coalescence of cracks are captured by a properly developed rate-dependent cohesive constitutive law. The mesoscale model is validated through comparison with experimental results. The crack evolution in the concrete under dynamic direct tensile loading conditions is explicitly presented, and the effects of the aggregate volume fraction and ITZ properties on the dynamic tensile strength enhancements are studied. The results indicate that material heterogeneity significantly influences the fracturing process and damage distribution. The dynamic tensile strength of concrete exhibits a two-strain rate regime dependence on the aggregate volume fraction concerning the strain rate. The influence of the mechanical properties of the ITZ on the dynamic tensile strength of concrete increases with the increasing strain rate.

Plastic recovery and strength enhancement of pre-deformed AZ31B magnesium alloy using transient strong pulse current

Magnesium alloy components are mainly used in aerospace and automotive fields, but poor deformation ability at room temperature restricts their application in other industries. To address this issue, electrically-assisted technology is employed to enhance plasticity of alloys. However, conventional method weaken strength and intensify surface oxidation of such alloys because of prolonged action of current. In view of the above, pre-deformation (PF) treatment in combination with transient induced pulse current treatment (TIPCT) is proposed in the present work so as to balance between plasticity recovery and strength of AZ31B alloy. The results show that the total elongation of PF sample and the corresponding TIPCT specimen first increases and then decreases with the increase in PF percentage under the same voltage. At the same PF percentage, the total elongation of PF and TIPCT specimens also presents the same trend as the voltage increases. At the same time, the total elongation in PF and TIPCT specimens is greater than that of the as-received sample. The maximum total elongation is achieved at the PF percentage of 16% and the voltage of 6kV, being 35% higher than that in the as-received sample. The improvement in total elongation is due to activation of more non-basal dislocations induced by TIPCT and the appropriate amount of microcracks generated by PF. In addition, the TIPCT process also improves the yield strength even if the PF percentage and voltage are changed. Besides that, the work hardening induced by PF treatment and instantaneous action of TIPCT process are the key factors enhancing yield strength. Moreover, comprehensive mechanical properties of TIPCT sample are found to outperform those after direct pulse current treatment (DPCT) under the same PF percentage. Therefore, the proposed composite process provides a feasible scheme to enhance strength and elongation of Mg sheets.

Strengthening flat-die friction self-pierce riveting joints via manipulating stir zone geometry by tailored rivet structures

Achieving high-strength joints with flat surfaces is of significant importance for reducing wind resistance and enhancing aesthetic appeal. In this study, a novel flat-die friction self-piercing riveting (flat-die F-SPR) process is proposed. The rivet flaring without die guidance was achieved through the sophisticated design of rivet structures. Three types of rivets with different internal structures were designed to manipulate the base material flow and microstructure evolution during the joining process. Based on the method of emergency stop, the load-stroke curves, evolutions of macroscopic morphology, and microstructure of the joints made with different rivets were investigated. A novel mechanism for solid-state bonding of joints was proposed to elucidate the generation and evolution of fine grain regions. The results indicate when downward pressure is applied to the material inside the rivet cavity, a central stirring zone appears. By using a rivet with an annular boss structure, the base material flows continuously into the stirring zone and piled up in the rivet cavity, forming a unique conical-shaped fine grain zone. Finally, a comprehensive assessment of the strength of different types of joints and the transition of the fracture modes were conducted based on different lower sheet thicknesses. The joints of Rivet_B and Rivet_C demonstrate 11.1% and 6.9% strength enhancement compared with the joint of Rivet_A, respectively. Two strategies for enhancing the strength of solid-state bonding are proposed by analyzing the joint strengthening mechanism, which offers insights for the optimizations of rivet structures.

Graphene nanoplatelet additive impact on compression and bending strength of S-2 glass face-sheet honeycomb sandwich panels: An experimental study

In this study, the three-point bending, edge-wise, and flat-wise strengths of Nomex® sandwich structures with un-doped S-2 glass fiber face-sheet (Neat/S-2/glass) and those with Graphene nanoplatelet-doped S-2 glass fiber face-sheet (GNPs/S-2/glass) were examined parametrically. In the macroscopic images obtained post-experimentation, the damage to the structures’ face layer, core, and interface with GNP (graphene nanoplatelet) additives was visualized. Morphological images depicting the damaged structures were obtained by applying image processing techniques to the macroscopic images. Finally, the fracture mechanisms of fiber/fiber and fiber/matrix interfaces within the shell layers were examined in SEM images. As a result of the study, the addition of GNPs increased the strength of the interfaces between the fiber layers and the fiber core within the face layers of S-2 glass face-sheet Nomex® sandwich structures, leading to a 40% enhancement in bending strength, a 14% improvement in core compressive strength, and a 2.85% increase in edge-wise compressive strength. Moreover, the delamination damage between the face layer and the core, which undermines the structural integrity of the sandwich structure, was not observed in GNPs/S-2/glass sandwich structures. Thus, the damage propagation throughout the sandwich structure contributed to enhancing its load-carrying capacity. The collapse extent of the sandwich structures, determined through image processing, measured 8676 mm in Neat/S-2/glass sandwiches, whereas it amounted to 10,410 mm in GNPs/S-2/glass sandwiches. The inclusion of GNPs additive augmented the collapse strength of the sandwich structure by 19.9%. Utilizing GNPs as a filler in the matrix material has been recognized as a practical approach to enhancing the mechanical strength of sandwich structures.

Experimental investigations on sustainable mortar containing mining tailing as partial replacement of fine aggregate

ABSTRACT The reuse of mining tailings contributes to minimizing the impact associated with the extraction of mineral resources. In this study, tailings were classified according to their mineralogy, and then 10% to 50% of the fine aggregate in the concrete was replaced by tailings. It was found a substantial enhancement in the compressive strength of concrete when incorporating mine tailings, increasing by 12% to 18%. The favourable outcomes can be attributed to the mineralogical compositions of the tailings. This innovative approach contributes to a noteworthy reduction in the environmental footprint associated with mining activities.

The Effect of a 12-week Plyometric Training on Growth Hormone, IGF-1 and Bone Health Indexes in Adolescent Boys

Background: During adolescence, physical activity influences bone mass, which is determined by both genetic and environmental factors. Objectives: This study examines the effect of plyometric exercises on serum markers in male adolescents, including growth hormone, vitamin D, parathyroid hormone, phosphate, and calcium. Methods: The study involved a sample of 30 male adolescents aged 15 years ± 6 months. The participants were divided into two groups: the first group, named the plyometric group (PG), included 15 adolescents who underwent plyometric training sessions three times a week for a duration of 12 weeks. The second group, called the control group (CG), consisted of 15 adolescents who only attended their normal school lessons without any physical training. Resting levels of GH, IGF-1, vitamin D, calcium, phosphate, and PTH were measured before and 48 hours after the last training session, along with bone mass density (BMD) measurements of the femoral neck, lumbar spine, and total body. To evaluate power, the vertical Sargent jump test was used. Results: The results indicate that the PG demonstrated significant improvements in BMD, explosive strength, GH, IGF-1, and vitamin D levels compared to the CG group (P < 0.05). Changes in phosphate, calcium, and PTH were not significant in the PG compared to the CG after 12 weeks of plyometric training (P > 0.05). Conclusions: The 12-week plyometric program resulted in notable enhancements in bone health, explosive strength, and anabolic hormones such as GH and IGF-1, as well as 25-hydroxyvitamin D serum levels.

Fabrication of kenaf fiber reinforced boron carbide fillers embedded epoxy matrix composite – An antimicrobial and structural analysis

This study investigates the incorporation of boron carbide (B4C) filler particulates into a kenaf fiber-reinforced epoxy matrix to explore its potential in lightweight applications, focusing on antimicrobial effectiveness, mechanical integrity, thermal properties, and microstructural characteristics. The composite material was formulated by blending varying seven different concentrations of boron carbide (0–50 g) and kenaf fibers (KFs) with an epoxy resin, aiming to achieve a balance between mechanical strength and minimal weight. Antimicrobial test revealed that the composite material, consisting of kenaf fiber reinforced with B4C particulates, exhibited significant antibacterial activity against common pathogens. Mechanical testing indicated that the addition of boron carbide and kenaf fibers significantly improved the tensile strength and flexural rigidity of the composites. Specifically, enhancements in tensile strength and flexural modulus were quantitatively analyzed, showing notable increases compared to the base epoxy resin. Scanning Electron Microscopy (SEM) was employed to examine the fracture surfaces following mechanical testing, revealing improved interfacial bonding between the kenaf fibers and the epoxy matrix due to the presence of boron carbide. This microscopic analysis also highlighted areas where stress distribution was optimized, contributing to the composite's enhanced mechanical properties.

Linear polydichlorophosphazene and Ti3C2Tx MXene nanohybrids: Synthesis and application to epoxy resin to improve the fire safety and mechanical properties

Enhancing the fire safety of epoxy resins (EPs) typically requires a significant amount of flame retardants, which often results in considerable degradation of their mechanical properties. To address this issue, a novel flame retardant known as PDCP@DPA@MXene was synthesized and integrated into EP to achieve notable improvements in flame retardancy, smoke suppression, and mechanical strength. By incorporating 1.5 wt% PDCP@DPA@MXene, the impact strength, tensile strength, and elongation at break of the resulting PDM-1.5 %/EP composite reached 12.1 kJ/m2, 57.4 MPa, and 13.0, respectively, reflecting enhancements of 63.5 %, 18.4 %, and 17.1 % compared to the pure EP. The enhancement in tensile strength may be attributed to the high rigidity of Ti3C2Tx MXene, which reinforces the EP matrix. Additionally, the intertwined structure of PDCP@DPA@MXene chains effectively mitigates material fracturing and absorbs impact forces, thus toughening the EP. The presence of phosphorus, nitrogen, and titanate in PDCP@DPA@MXene contributes to the formation of a more compact char layer. The PDM-1.5 %/EP sample achieved a V-0 rating in the vertical UL-94 test and exhibited a high limiting oxygen index of 32.0. Furthermore, the sample containing 2 wt% PDCP@DPA@MXene showed a significant reduction in peak heat release rate (p-HRR) and total heat release (THR), recording values of 689 kW/m2 and 71.9 MJ/m2, which are decreases of 45.1 % and 26.9 %, respectively, compared to pure EP. Additionally, the incorporation of PDCP@DPA@MXene led to a reduction in CO production. These flame-retarded EPs demonstrate strong potential for various applications due to their elevated glass transition temperature and robust thermal stability.

Enhancement of interfacial shear strength of shape memory alloy–polylactic acid composite and predictive modeling through cohesive zone modeling approach for 4D printing

Enhancement of interfacial shear strength of shape memory alloy–polylactic acid composite and predictive modeling through cohesive zone modeling approach for 4D printing

Identifying clinically meaningful muscle power enhancements and their functional correlates in hospitalized older patients.

This study aimed to determine the threshold of muscle power and strength enhancements that lead to functional gains after exercise intervention in an acute care unit. A total of 302 older patients (intervention: 169, control: 133) from two randomized clinical trials were included (mean age 86.7 years). We measured maximal strength (1RM) and muscle power via a velocity transducer during leg press exercise at 30% and 60% of 1RM. A multicomponent exercise program, including power training, balance, and gait exercises performed over 3 to 6 consecutive days, served as the intervention. We used an anchor-based method to correlate muscle function increases with the Short Physical Performance Battery (SPPB) and gait velocity (GVT) to define clinically meaningful improvements (CMI). In the intervention group, marked differences were found in maximal power at 30% of 1RM between SPPB responders and non-responders (relative 83.5% vs. 34.8%; absolute 33.0 vs. 12.8 W; P<0.05) and at 60% of 1RM (relative 61.1% vs. 22.4%; P<0.05). GVT responders demonstrated significantly greater improvements in both relative and absolute maximal power than non-responders at both 30% and 60% of 1RM (P<0.05), as well as greater absolute 1RM gains (21.2 vs. 15.2kg, P<0.05). CMI for muscle power based on SPPB and GVT ranged from 30.2% to 48.7%, whereas for 1RM, it was 8.2% based on GVT. Muscle power gains were most notable in patients with improvements in the SPPB and GVT, highlighting the critical role of muscle power in functional recovery in these patients.

Synergistic Effects of Korean Mistletoe and Apple Peel Extracts on Muscle Strength and Endurance.

Muscular strength and endurance are vital for physical fitness. While mistletoe extract has shown efficacy in significantly increasing muscle strength and endurance, its accessibility is limited. This study explores combining mistletoe and apple peel extracts as an effective muscle health supplement. Analyses of histology, RNA, and protein in the combined extract-treated mouse group demonstrated significant enhancements in muscle strength and endurance, evidenced by larger muscle fibers, improved mitochondrial function, and a higher ratio of type I and IIa muscle fibers. Combining half doses of each extract resulted in greater improvements than using each extract separately, indicating a synergistic effect. Pathway analysis suggests that the observed synergy arises from complementary mechanisms, with a mistletoe extract-induced decrease in myostatin (MSTN) and an apple peel extract-induced increase in IGF1, leading to a sharp rise in AKT, S6K, and MuRF1, which promote myogenesis, along with a significant increase in PGC-1α, TFAM, and MEF2C, which are critical for mitochondrial biogenesis. This research provides practical insights into developing cost-effective, natural supplements to enhance muscle performance and endurance, with potential applications in athletic performance, improving muscle growth and endurance in children, and addressing age-related muscle decline.

Study of multiscale mechanical properties of Al-Pd-Mn quasicrystals

Based on the quantum mechanics and molecular mechanics scales, the elastic and tensile mechanical properties of Al-Pd-Mn quasicrystals (QCs) are investigated by utilizing the first-principles and molecular dynamics (MD) methods. The density functional theory (DFT) is adopted to obtain all elastic constants, stability, elastic modulus, Poisson's ratio, anisotropy, Debye temperature of Al57Pd16Mn3 QCs. Simultaneously, the MD simulations are conducted to analyze the influence of temperature and strain rate on the stress-strain curves, atomic structures, and deformation mechanism. The results indicate that Al57Pd16Mn3 QCs are stable orthogonal structures and satisfy the Cauchy conditions. Additionally, the mechanical properties of Al-Pd-Mn QCs obtained by the first-principles are consistent with the MD and experimental results. The elastic properties of Al57Pd16Mn3 QCs are approximately isotropic. The elastic modulus and ultimate tensile strength of Al57Pd16Mn3 QCs always decrease with increasing temperature. An increase in the strain rate results in a negligible change in the elastic modulus but in a noticeable enhancement in the ultimate tensile strength and strain. The current results could provide essential theoretical insights for studying the mechanical properties of QCs, and extend the scope of multi-scale study in the field of QCs at microcosmic scale as well.

Efficacy of lower limb strengthening exercises based on different muscle contraction characteristics for knee osteoarthritis: a systematic review and network meta-analysis.

While strengthening exercises are recommended for knee osteoarthritis (KOA) treatment, the optimal type of muscle contraction remains unclear, with current research showing conflicting results. This network meta-analysis (NMA) aims to evaluate the efficacy of lower limb strengthening exercises based on different muscle contraction characteristics for KOA patients and provide clinical references. We conducted the NMA following the PRISMA-NMA. A comprehensive search of five databases (PubMed, Web of Science, CENTRAL, Embase, and SPORTDiscus) up to August 2024 identified randomized controlled trials (RCTs) investigating lower limb strengthening exercises in KOA patients. Control groups included receiving usual care, only providing health education, or no intervention at all. Outcomes analyzed included pain, physical function, quality of life, and muscle strength. Forty-one studies (2,251 participants) were included. Twenty-eight studies used rigorous randomization; eighteen reported allocation concealment. All had high performance bias risk due to exercise interventions. Regarding efficacy, isokinetic exercise ranked highest in pain relief (SMD = 0.70, 95% CI: 0.50-0.91, SUCRA = 82.6%), function improvement (SMD = 0.75, 95% CI: 0.57-0.92, SUCRA = 96.1%), and enhancement in muscle strength (SMD = 0.56, 95% CI: 0.34-0.78, SUCRA = 90.1%). Isometric exercise ranked highest in improving quality of life (SMD = 0.80, 95% CI: 0.28-1.31, SUCRA = 90.5%). Mixed strengthening exercise ranked lowest across all outcomes. High-frequency interventions (≥5 times/week) showed superior pain relief compared with low-frequency (≤3 times/week) for isotonic, isometric, and isokinetic exercise. This NMA suggests isokinetic exercise may be most effective for pain, function, and muscle strength in KOA patients, while isometric exercise benefits quality of life most. Mixed strengthening exercise ranked lowest across all outcomes. High-frequency interventions appear more effective than low-frequency ones. These findings support personalized KOA treatment, considering efficacy, accessibility, and patient-specific factors. Study biases, heterogeneity, and other limitations may affect result reliability. Future research should focus on high-quality studies with standardized protocols and analyze dose-response relationships to refine KOA treatment strategies. https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024582525, identifier: CRD42024582525.

Multiscale model for concrete cured under geothermal environment: Theoretical analysis and experimental validation

Concrete poured as linings of geothermal tunnel would deviate normal curing condition. A multiscale model based on continuum micromechanics, accounting for temperature-dependent factors, is established from the cement paste level to the concrete level. This model predicts the physical properties and compressive strength of concrete and is validated against measured strength, which incorporates the impact of high-temperature curing on the hydration degree, density of C-S-H, and chemical shrinkage of cement. Evolutions of the average hydration degree and compressive strength of concrete were experimentally investigated to this end, and then simulated with multiscale approach. The specimens were subjected to curing temperature 20°C, 40°C, 60°C, and 80°C for first 7 days while maintaining constant relative humidity of 100 %, and then water curing at 20°C for the rest days till tests. The high-temperature curing accelerates the hydration process, but the variance in hydration degree between standard temperature (20°C) and high-temperature conditions diminishes with prolonged water curing. An enhancement in compressive strength is also observed in the early stages of high-temperature curing, succeeded by a decline compared with standard curing after the 50th curing day. Quantitative analysis reveals that volume fractions of hydrates and porosity subjected to high-temperature curing show a substantial increase in the first 7 curing days, and the denser layer of hydration products formed on cement slows down the hydration in later curing ages. The complex evolution of strength in concrete undergoing high-temperature curing is influenced by temporal consideration (the hydration degree) and spatial considerations (the density of C-S-H and the chemical shrinkage of cement). The surge in hydration significantly contributes to strength promotion in early stages. However, the pivotal factor leading to strength deterioration is the increase of porosity when the difference in the hydration degree is less than 0.065.

Sodium metasilicate-activated one-part geopolymer concrete: Impact strength assessment with bottom ash substitution and fiber reinforcement

This study aims to investigate the effect of fibers on the impact strength of fibrous one-part geopolymer concrete (OPGC) to mitigate its brittleness. This research examines the impact strength of OPGC activated with sodium metasilicate pentahydrate, utilizing fly ash as a precursor material. The study uniquely explores the effects of bottom ash, substituted at varying levels (25 % to 100 %) for sand, within the OGPC matrix. Additionally, incorporating two distinct fiber types, polypropylene and kenaf, individually at 0.5 % and in a hybrid combination at 0.25 % each, offers a fresh perspective on fiber reinforcement in OGPC. Scanning electron microscopy and X-ray diffraction provide critical insights into the microstructural and mineralogical properties of the developed OPGC. The impact strength of OPGC with this specific combination of materials has not been previously investigated by any researchers, establishing the novelty of this study. Results revealed that the combination of fibers with 25 % BA exhibited a synergistic effect, leading to a notable enhancement in impact strength. Conversely, the impact strength declined with other combinations of materials. Polypropylene fibers demonstrated the highest performance in terms of impact strength for OPGC, followed by the hybrid fiber combination, with kenaf fibers exhibiting the lowest performance in this regard.

Enhanced mechanical and damping properties of Cu-Modified Al-Ni eutectic alloys: Solid-solution and precipitation hardening effects

The study aimed to analyze the mechanical properties, precipitation strengthening, and microstructure of Al-Ni-Cu alloys to understand their enhanced characteristics. Additionally, the damping behavior was examined using a dynamic mechanical analyzer across a continuous heating temperature range with frequencies from 0.5 to 15 Hz. The experimental results indicate that the Al-Ni eutectic alloy, which exhibits an ultrafine Al3Ni intermetallic fiber-reinforced Al matrix, transitions to a dendritic-ultrafine eutectic composite structure. The Cu-containing alloys exhibit two distinct primary phases: α-Al and Al-Ni-Cu ternary intermetallic compounds. The eutectic matrix transforms from Al-Al3Ni to Al-Al7Cu4Ni, and subsequently to Al-Al2Cu. These microstructural evolutions result in an enhancement of the tensile yield strength from 170 MPa to 440 MPa, with additional hardening achieved through aging-induced precipitation. Moreover, the damping capacity improves with the addition of Cu at elevated temperatures, and there is an increase in frequency dependence. This paper will discuss the microstructural features, mechanical properties, deformation behaviors, and damping properties in detail.