Improvement Of Mechanical Properties Research Articles

Significant Improvement in Mild Steel Mechanical Properties with Cu-Fe-Ti Alloy Coatings

This research examines the mechanical properties of mild steel using the electrodeposition of ternary Cu-Fe-Ti alloys with varying Ti compositions at room temperature. The coating process maintained constant pH, current density, deposition time, and temperature. X-ray diffraction analysis revealed single-phase compositions with a face-centered cubic (fcc) structure for all electrodeposited samples. The crystallite sizes ranged from 14-17 nm. The lattice parameters of the Cu-Fe-Ti alloys strongly depended on the Ti concentration. Scanning electron microscopy images showed smoother surfaces with increasing Ti content. Energy-dispersive X-ray spectroscopy confirmed the presence of Cu, Fe, and Ti in the coatings. The Vicker hardness increased from 255 HV to 444 HV. With more Ti in solution, the Cu-Fe-Ti alloy coating thickness on mild steel decreased from 63 μm to 25 μm, and the surfaces became smoother. Thus, the improved mechanical properties correlate with Ti concentration, lattice parameter, crystallite size, and coating thickness. Enhanced mechanical properties of mild steel with Cu-Fe-Ti alloy coatings offer potential for improved durability and performance in radiation therapy equipment and medical imaging devices.

Grain refinement and mechanical properties improvement of AlCuFeCoNi high-entropy alloy coatings fabricated by resonant ultrasonic assisted laser cladding

Laser cladding technology has gained significant popularity for the preparationof high-entropy alloy (HEA) coatings. This is primarily due to its notable benefits, such as a low dilution rate and a robust bonding capability. However, the laser cladding process’s rapid solidification effect and the high entropy impact led to the formation of defects in the coatings, such as non-uniform organization and elemental segregation. In this paper, the resonant ultrasonic vibration was used to regulate the organization and improve the microhardness and friction properties of the AlCuFeCoNi HEA coatings. The experimental findings demonstrate that ultrasonic vibration enhances both the width and depth of the coating’s molten state, while simultaneously reducing the height of the coating. Before and after the introduction of ultrasonic vibrations, the coating consists of two phases, body-centered cubic (BCC) and face-centered cubic (FCC). However, the magnitude of the FCC phase significantly increased with higher power. The internal grains of the coating were significantly refined by ultrasonic vibration, and the average grain size was refined from 68.34 μm to 35.28 μm, and the area occupied by equiaxial grains also increased with the increase of ultrasonic power, and the segregation of the FCC phase dominated by Cu elements was suppressed. When the ultrasonic power was 30 %, the microhardness of the coating was increased from 553.19 ± 5.15 HV0.2 to 600.47 ± 3.61 HV0.2. The addition of ultrasonic vibration increased the wear resistance of the coating and lowered the coefficient of friction from 0.558 to 0.409. Furthermore, the friction mechanism of the coatings before and after the addition of ultrasonic vibration did not change, and both were abrasive wear with slight oxidative wear.

Collaborative improvement of mechanical and electrical properties of Cu–Ni–Co–P alloys via regulation of nanophase precipitation behavior

Owing to their excellent strength and electrical conductivity, Cu–Ni–Co–P alloys present strong potential as next-generation materials for integrated circuits in electronic information systems. However, these outstanding properties are closely tied to the precise control of nanophase precipitation behavior within Cu-based alloy systems. Herein, the design of alloy composition was combined with aging treatment to regulate the nanoprecipitation process. Furthermore, the effects of P content and aging treatment conditions, including temperature and duration, on the microstructure and the mechanical, and electrical properties of Cu–Ni–Co–P alloys were systematically investigated. The findings reveal that Cu–0.3Ni–0.3Co–0.16P alloys, when aged at 500 °C for 4 h, primarily consist of a Cu-rich matrix interspersed with numerous nanoprecipitates. These nanoprecipitates were identified as the hexagonal CoNiP phase, precipitating in Guinier–Preston (GP) zones and maintaining a coherent relationship with the Cu matrix. The as-annealed Cu–0.3Ni–0.3Co–0.16P alloys demonstrated a tensile strength of 652.9 MPa, a yield strength of 631.2 MPa, a Vickers hardness of 203.2 HV, and an electrical conductivity of 66.4 %IACS. Aberration-corrected scanning transmission electron microscopy revealed that G.P. zones suppressed the coarsening of the CoNiP phase, thereby enhancing the mechanical strength of the Cu–Ni–Co–P alloys. The strength analysis calculations suggest that fine-grain and precipitation strengthening mechanisms are the predominant factors in improving the mechanical strength of these alloys. This study provides valuable insights into the development and manufacturing of high-performance Cu-based alloys for advanced applications in the electronics industry.

Unraveling the modulation art of ordered nanomesh-like hydration product on fiber-cement interfaces: Insights from fishing net inspiration

The morphology of interface hydration products is crucial as it directly determines the interface mechanics. Inspired by the fishing nets, we employed photo-grafted active copolymer Poly(vinylpyrrolidone-co-acrylic acid) on the inert glass fibers. Providing a template for PVP-co-PAA maintains its regulatory capability in cement paste. For the first time, ordered nanomesh-like hydrated calcium silicate (CSH) with average pore diameter of 30 nm are developed in cement paste. The interface strength and energy absorption increased by 90 % and 253 %, respectively. XPS and SEM revealed that the multi-scale regulation mechanisms originated from the preferential adsorption and stable dispersion of Ca2+ result from the strong electronegativity and steric hindrance of pyrrolidone rings. CSH nuclei (60 nm) dispersed well on fiber templates, stacked along fiber surfaces, without collapse or tilt, intertwined into nanomesh. Nanomesh-like CSH in cement paste holds significant potentials for the improvement of mechanical properties of fiber-cement interfaces, contributing to construction sustainability.

Surface mechanical property and residual stress stability of nanostructured CNT/Al-Cu-Mg composites induced by shot peening

Shot peening (SP) is recognized for its capacity to enhance surface strength and induce compressive residual stresses (CRS). Nevertheless, quantifying the mechanical property improvements in thin shot peened layers remains challenging with traditional methods. In this study, CNT/Al-Cu-Mg composites were subjected to shot peening. The microstructure evolution of the peened layers along the layer depth direction was investigated by XRD and TEM. Meanwhile, the changes in the mechanical properties of the shot peened layers and the release rules of CRS during tensile cycling at different numbers loads were measured by an in-situ X-ray stress analyzer and a micro-tensile device in conjunction with the Von Mises stress criterion. The results showed that SP generated the nano-gradient deformation layer with nanograins size of 50–100 nm near the surface. The yield strength of the surface layer was increased from 352 MPa before SP to 435 MPa, an increase of 23.6 %. Moreover, the observation of fracture morphology indicated that SP reduced the material plasticit moderately and the agglomeration of the Al2Cu. In addition, in the case of a certain CRS on the initial surface, the relaxation of CRS was correlated with the magnitude of applied loads and the number of cycles and couldn't occur when the applied loads is below a specific value.

Improvement of Mechanical Properties and Corrosion Resistance of As‐Extruded Mg–2Zn–2Al–0.3Mn Alloy Through Y Addition

The microstructure of as‐extruded Mg–2Zn–2Al–0.3Mn–xY (0 ≤ x ≤ 5 wt%) alloys are investigated, revealing the influence of grain size and second‐phase particle size on the mechanical properties and corrosion resistance of alloys. Additionally, the alloy composition is optimized. In the results, it is indicated that all alloys undergo complete dynamic recrystallization. The average dynamic recrystallization grain size decreases, accompanied by the appearance of Al2Y and (Al, Zn)11Y3 particles whose contents and sizes increase as Y content increases. Therefore, the mechanical properties improve due to fine grain strengthening and fine particle dispersion strengthening, while corrosion resistance benefits also from the grain refinement at Y contents between 0 and 3 wt%. A rapid increase in size and number of larger second‐phase particles leads to a decrease in the alloys’ mechanical properties corrosion resistance, with excess addition of Y. Accordingly, an optimized Y addition is determined to be 3 wt% in this study.

Developing Innovative Nano-Engineered Lightweight Foamed Concrete Incorporating Iron Oxide (II, III) with Enhanced Mechanical and Transport Properties

Recently, scientists have focused substantial attention on the incorporation of nanoscale components in cement-based materials. Iron oxide (II, III) nanoparticles (IONPs) have garnered significant attention in nanoparticle research. This paper portrays preliminary discoveries of an investigation assessing the characteristics of foamed concrete (FC) with the presence of IONPs. A comprehensive assessment of characteristics was conducted, including its workability, axial compressive strength, bending strength, tensile strength, apparent porosity and water absorption capacity. Furthermore, scanning electron microscope examination was performed and evaluated. The results indicate a significant enhancement in the FC strength characteristics, with 28-day compressive, tensile, and bending strengths improving by up to 70, 76 and 52 %, respectively, with the inclusion of 3 % IONPs. Nonetheless, adding IONPs beyond 3 % did not yield significant improvements in mechanical properties. With a rise in IONPs from 1 to 5 %, the FC exhibited significant improvements in apparent porosity and water absorption. The decreasing pore size in FC containing IONPs was found to be the cause of the anomalies. A significant alteration in the arrangement of pore dimensions was noted in FC mixtures when the amounts of IONPs were modified. Results from this investigation emphasise the prospective benefits associated with integrating IONPs into FC, that could boost its entire characteristics.

Nacre-like aluminum/PVDF energetic composites with enhanced combustion and mechanical properties

This study introduces a nacre-inspired aluminum (Al) flake/polyvinylidene fluoride (PVDF) energetic composite, designed to enhance its combustion and mechanical performance for propulsion applications. In comparison to Al/PVDF composites utilizing spherical micron-sized Al particles, the nacre-like Al/PVDF composite with aligned Al flakes showed a 115% enhancement in tensile strength, a 10% increase in toughness, but a 75% reduction in elongation. A hybrid composite, combining aligned Al flakes and spherical particles, demonstrated a balanced improvement in mechanical properties: a 122% increase in tensile strength, a 96% rise in toughness, and a more modest 29% reduction in elongation. Furthermore, the aligned Al flakes enhanced the thermal conductivity of the composites, resulting in a 53% faster burn rate of Al/PVDF, suggesting that microstructural tuning through flake alignment and particle incorporation influences both mechanical and combustion properties. These findings highlight that nacre-like microstructure can effectively augment the performance of Al/PVDF energetic composites, indicating potential applications in propulsion.

Improving the strength and reliability of mortar composites with zeolite substitution

Cliniptilolite zeolite, a naturally occurring pozzolan, is a viable supplemental cementitious material (SCM) for reducing the carbon footprint generated by the cement industry. While previous literature has explored the use of natural zeolite as an SCM for cement composites, this investigation advances understanding on the effectiveness of natural zeolites as an SCM in three phases. In Phase I, two distinct forms of zeolite (Z1 and Z2) in relative mineralogical compositions and particle sizes were incorporated into mortar composites to replace ordinary Portland cement (OPC) at concentrations up to 20 wt% and characterized over a period of 28 days. Based on the superior performance of the higher clinoptilolite content zeolite (Z2), it was used in Phase 2 to evaluate the effect of zeolite substitution. In Phase 3, the reliability of the resultant composites prepared with Z2 were assessed using Weibull statistics. The inclusion of Z2 type zeolite at #200 mesh size and 10 % concentration yielded compressive strength and reliability comparable to the OPC control mortar at day 7, but significantly greater strength and reliability from day 14 onward. Porosity detailed by microCT suggests that increasing zeolite content to 15 % and greater results in unreacted zeolite that is detrimental to strength. The findings further establish the merits of natural zeolite as an SCM material and distinguish what is necessary for further improvements in mechanical properties of zeolite cement composites.

The Effect of Preheating on the Mechanical Properties of AISI 1037 and AISI 304 Welded Joints Using Shielded Metal Arc Welding

This study explores the effect of preheating on the toughness of dissimilar welded joints between AISI 1037 and AISI 304 steels, using Shielded Metal Arc Welding (SMAW) and E309-16 electrodes. The innovation of this approach lies in assessing how preheating temperatures influence the mechanical properties of such welds. Preheating temperatures ranged from 150 °C to 300 °C, with impact testing revealing a notable increase in toughness, from 6.01 Joules at 150 °C to 19.57 Joules at 300 °C. Hardness tests indicated a maximum hardness of 313 VHN in the fusion zone and a minimum of 185 VHN in the AISI 304 area. Compared to non-preheated joints, preheating significantly enhanced impact strength and altered the fracture mode from brittle to ductile. Macrostructural and microstructural analyses with optical microscopy and SEM showcased changes in fracture surfaces and microstructural evolution, highlighting the improvement in mechanical properties due to preheating. These findings demonstrate that preheating critically enhances the toughness and overall performance of dissimilar metal welds, making it a valuable technique in industrial applications where enhanced joint toughness is crucial.

Prediction of frictional behaviour through regression equations: A statistical modelling approach validated with machine learning

Prediction of frictional behaviour through regression equations: A statistical modelling approach validated with machine learning

Extreme Toughening of Conductive Hydrogels Through Synergistic Effects of Mineralization, Salting-Out, and Ion Coordination Induced by Multivalent Anions.

Developing conductive hydrogels with both high strength and fracture toughness for diverse applications remains a significant challenge. In this work, an efficient toughening strategy is presented that exploits the multiple enhancement effects of anions through a synergistic combination of mineralization, salting-out, and ion coordination. The approach centers on a hydrogel system comprising two polymers and a cation that is highly responsive to anions. Specifically, polyvinyl alcohol (PVA) and chitosan quaternary ammonium (HACC) are used, as PVA benefits from salting-out effects and HACC undergoes ion coordination with multivalent anions. After just 1 h of immersion in an anionic solution, the hydrogel undergoes a dramatic improvement in mechanical properties, increasing by more than three orders of magnitude. The optimized hydrogel achieves high strength (26 MPa), a high Young's modulus (45 MPa), and remarkable fracture toughness (67.3 kJ m-2), representing enhancements of 860, 3200, and 1200 times, respectively, compared to its initial state. This breakthrough overcomes the typical trade-off between stiffness and toughness. Additionally, the ionic conductivity of the hydrogel enables reliable strain sensing and supports the development of durable supercapacitors. This work presents a simple and effective pathway for developing hydrogels with exceptional strength, toughness, and conductivity.

Modeling of thermal evolution and fluid flow during synchronous induction-assisted laser wire deposition

Introducing induction heating into laser deposition, which is referred to as synchronous ultra-high frequency induction-assisted laser deposition (SUHF-LD), not only alleviates the defects of stress concentration and microcracks, but also utilizes the electromagnetic stirring effect to refine grain size for improvement in mechanical property of the deposited components. Given that the incorporation of induction heat into laser deposition make the thermal evolution and flow behavior more complex. To this end, a numerical model coupled with multi-physical fields (such as electromagnetic/ temperature/ flow field) is developed to reveal the impact of Lorentz force on the heat transfer and fluid flow in the molten pool. Results show that the adjunction of the induction heat in laser deposition accelerates the flow velocity and decreases the maximum temperature of the molten pool due to the enhanced thermal convection in molten pool caused by Lorentz force. Investigation on the varying induction heat parameters indicates that the flow velocity of the molten pool is increased respectively by 23.8 % and 33.3 % under the condition of 800 kHz/1000A and 900 kHz/1400A compared to laser deposition. The SUHF-LD hybrid deposition simulation demonstrates that the temperature distribution and macro-geometry of the deposited track agree well with the experimental results. Furthermore, the multi-layer single-pass deposited tracks fabricated by SUILD hybrid deposition exhibits excellent tensile performance and wear resistance, indicating the hybrid deposition process can be widely applied in industry fields.

Achieving further refinement of grain structure and improvement of mechanical properties in Al-12Si-4Cu-2Ni-1Mg alloy by Al-Ti-C-B master alloy addition and deep cryogenic treatment

Achieving further refinement of grain structure and improvement of mechanical properties in Al-12Si-4Cu-2Ni-1Mg alloy by Al-Ti-C-B master alloy addition and deep cryogenic treatment

Synergistic effect of alkali treatment and graphene filler on the mechanical characteristics of nettle fiber reinforced polymer composite

This study examines the synergistic effects of alkali treatment and the addition of graphene fillers to nettle fiber-reinforced polymer (NFRP) composites. NFRP composites were fabricated using NaOH-treated nettle fibers at concentrations of 3%, 5%, and 7%. Gr-NFRP composites were produced by varying the graphene content (1wt%, 2wt%, and 3wt%) in the epoxy resin that impregnated 5% NaOH-treated nettle fibers. The composites were prepared using a hand layup combined with a compression molding technique. A comprehensive analysis of the physical, mechanical, and wear properties of the treated NFRP composites was performed. FTIR analysis confirmed the effect of alkali surface treatment on the nettle fibers, whereas SEM was employed to examine the morphology of the fractured specimens. The experimental results revealed that a 5% NaOH solution was the optimal concentration for improving the characteristics of nettle fibers within the polymer composite. Moreover, the inclusion of 2wt% graphene noticeably enhanced the mechanical properties of the NFRP composites, resulting in increases of 21%, 17%, 65%, and 10% in the tensile strength, flexural strength, impact strength, and Shore D hardness, respectively. The wear resistance improved by 38%, and the water absorption decreased by 32%. SEM images revealed that a balanced contribution between fiber breakage and pullout was the primary failure mechanism in the Gr-NFRP composites. The NFRP composite containing 2wt% graphene demonstrated significant improvements in both mechanical and wear properties, along with reduced water absorption, making it a highly promising material for structural applications.

Mechanism and performance of thermal radiation recycling for in-space 3D printed continuous carbon fibre-reinforced PEEK composites

ABSTRACT The benefits of space recycling lie in reducing launch mass and achieving self-sufficiency. For 3D printed continuous fibre-reinforced composites (CFRCs), a reverse melt recycling technology was proposed, involving heating resin opposite to the 3D printing path and continuously peeling-off the fibres from the melt. An infrared radiation heating recycling device suitable for a vacuum environment was designed and the temperature distributions were optimised, achieving recycling of continuous carbon fibre-reinforced polyether ether ketone (CF/PEEK) thin-walled rotational structures. The recycled filaments with diameters of 0.7 and 0.8 mm could achieve good surface quality and low pore defects. The porosity decreased from 11.2% of original samples to 5.7% of remanufactured samples, leading to improvements in mechanical properties with flexural strength and modulus increased by 4.8% and 50.8% respectively. Overall, the recycling technology emphasised a non-degradation recycling solution for 3D-printed CFRCs in space to form a full lifecycle application model for space composites.

Improvement in Mechanical and Corrosion Properties of Laser and electron Beam Welded AISI 304 Stainless Steel Joints by Laser Shock Peening

Improvement in Mechanical and Corrosion Properties of Laser and electron Beam Welded AISI 304 Stainless Steel Joints by Laser Shock Peening

Effect of industrial multi-walled carbon nanotubes on the mechanical properties and microstructure of ultra-high performance concrete

To enhance the safety and functionality requirements of engineering structures, carbon nanotubes are used to improve the performance of concrete. However, their high cost limits their large-scale application. In this study, industrial multi-walled carbon nanotubes (IMWCNT) were employed to ultra-high performance concrete (UHPC) to achieve a balance between nanomodification and economy. The effects of different IMWCNT contents on the flowability, mechanical properties, and water resistance of UHPC were investigated. Moreover, the hydration products, microstructure, and fiber–matrix interface characteristics of UHPC specimens were analyzed using thermogravimetric analysis and scanning electron microscopy. The incorporation of appropriate amounts of IMWCNTs could effectively improve the mechanical properties and crack resistance of UHPC and partly prevent the infiltration of water into the matrix. Adding 0.1 wt% IMWCNTs resulted in optimal mechanical properties, and the flexural/compressive strengths of fiberless UHPC mortar and fibrous UHPC (2 vol% steel fibers) were increased by 6.7/5.2 % and 8.5/11.3 %, respectively. Microstructural analysis of the samples showed that uniformly dispersed IMWCNTs can enhance cement hydration and bridge the cracks at the microscale and nanoscale. In addition, incorporating an appropriate amount of IMWCNTs in UHPC reduced the porosity of its fiber–matrix interface and optimized steel fiber distribution in the matrix. Cost-benefit analyses results showed that although the addition of IMWCNTs increases the manufacturing cost of fibrous UHPC, their addition in moderate amounts (0.1 wt%) does not adversely affect the economic index due to the improvement in mechanical properties.

Optimization of Amylose to Amylopectin Ratio and Degree of Substitution in Quaternized Starch as a Tool to Improve Paper Strength

AbstractCationic starch serves as a prevalent wet‐end additive in the papermaking industry. Yet, the definitive effects of the ratio between the two principal components—amylose (AM) and amylopectin (AP)—and the degree of substitution (DS) on the mechanical strength enhancement of paper sheets remain incompletely understood. This study synthesizes a series of quaternized amylose (QAM) and quaternized amylopectin (QAP) with varying DS levels and blended these derivatives in diverse ratios. Subsequently, these mixtures are integrated into pulp suspensions to ascertain the DS and the AM‐to‐AP ratio that optimize paper strength. These results indicate that a QAM‐to‐QAP blend with a DS of 0.08 at a ratio of 2:8 yielded the most pronounced improvement in paper mechanical properties. This precise formulation significantly enhances tensile, burst, and tear strength indices, increasing by approximately 55.0%, 44.4%, and 78.4%, respectively, under the most favorable conditions and with an additive dosage of 1 wt.%. This investigation provides substantive and actionable knowledge for selecting starch additives in the wet‐end of papermaking, which can significantly augment the efficiency and efficacy of paper manufacturing processes.

Preparation and characterization of nanocomposites based on natural rubber/chlorobutyl rubber/graphene nanoparticle: Effect of feeding sequences, mixer type and nanoparticle concentration

AbstractBlends of natural rubber (NR)/chlorobutyl rubber (CIIR) (50/50), along with their nanocomposites containing varying amounts of graphene nanoparticles (GNPs) with and without silane, were prepared using different feeding sequences and mixers. The results indicated that when GNP was first mixed with NR before adding CIIR, the highest GNP content was found in NR; the oxygen permeability and diffusion coefficient decreased significantly by 37% and 55%, respectively. Conversely, when graphene was initially added to CIIR, it was distributed in both rubbers and at the interface, enhancing phase interaction and achieving a finer morphology. This sample exhibited the greatest improvement in mechanical properties due to specific localization of GNP and increased crosslink density. Using an internal mixer instead of a two‐roll mill improved graphene dispersion, reduced curing time, and enhanced mechanical properties. Although the presence of silane reduced graphene dispersion, it improved mechanical and barrier properties due to increased crosslink density. Oxygen permeability was reduced by up to 36% at 3 phr of GNP content with silane. This research proves that the mixing order and the type of mixing equipment are crucial in determining the final performance of rubber composites, as they significantly influence the dispersion and localization of fillers.Highlights NR/CIIR/GNP nanocomposites were prepared by different methods and evaluated. Adding NR/GNP to CIIR led to more presence of GNP in NR and lower permeability. By adding CIIR/GNP to NR, GNP were placed more at interface, modulus improved. Mixing in an internal mixer improved GNP dispersion compared to a two‐roll mill. Silane improved mechanical and barrier properties of NR/CIIR/GNP nanocomposite.