Microstructure Of Nanocomposites Research Articles

Investigations on Microstructure and Mechanical Properties of HAp Nanocomposites reinforced with ZrO2 and TiO2

In the contemporary context, approximately 15 million individuals in India grapple with bone-related issues stemming from accidents, fractures, bone mass depletion, and the natural aging process. To address this challenge, a diverse array of biomaterials has been innovated to rectify or enhance bone deficiencies within the human body. Nevertheless, over the past decade, calcium phosphate-based bioceramic materials have gained significant prominence as synthetic alternatives for bone and dental applications in the fields of orthopaedics and dentistry. One such bioactive ceramic, Hydroxyapatite (HAp), boasts exceptional versatility and can find utility in both dental and orthopaedic contexts. In the current research, exhaustive research was conducted to explore the impact of HAp/(ZrO2+TiO2) hybrid nano-composites synthesized through a mechanical synthesis process employing high-energy ball milling (HEBM), incorporating varying weight proportions. The resulting “HAp/(ZrO2+TiO2) nano-composites” were subjected to characterization through scanning electron microscopy combined with energy-dispersive X-ray spectroscopy (SEM-EDX) and X-ray diffraction (XRD). Furthermore, the study assessed the influence of these nano-composites regarding the HAp nano-composites’ mechanical characteristics.

A Detailed Study on using Novel LM 25 Aluminium Alloy Hybrid Metal Matrix Nanocomposite for Nuclear Applications.

This article describes the use of graphite(Gr) and boron carbide (B4C) as multiple nanoparticle reinforcements in LM25 aluminum alloy. Because boron carbide naturally absorbs neutron radiation, aluminium alloy reinforced with boron carbide metal matrix composite has gained interest in nuclear shielding applications. The primary goal of the endeavor is to create composite materials with high wear resistance, high microhardness, and high ultimate tensile strength for use in nuclear applications. Science and Technology have brought a vast change to human life. The human burden has been minimized by the use of innovation in developing new and innovative technologies. To improve the quality of human life, fresh, lightweight, and creative materials are being used, which play a vital role in science and technology and reduce the human workload. Composite materials made of metal are being used because they are lightweight. Neutron absorption, high ultimate strength, high wear resistance, high microhardness, high thermal and electrical conductivity, high vacuum environmental resistance, and low coefficient of thermal expansion under static and dynamic conditions are all demands for the hybrid metal matrix composites utilized in nuclear applications. • Stir casting is used to create the novel LM 25 aluminum alloy/graphite and boron carbide hybrid nanocomposites. • The mechanical properties such as ultimate tensile strength, yield strength, percentage of elongation, microhardness, and wear behavior are calculated. • Three analyses are performed: microstructure, worn surface analysis, and fracture analysis of the tensile specimen. • Stir casting process< • Tensile, Hardness, Wear Test • Materials Characterization - FESEM, Optical Microscopy, EDS< Results: The mechanical properties values are 308.76 MPa, 293.51 MPa, 7.8, 169.2 VHN, and 0.01854mm3/m intended for ultimate tensile strength, yield strength, percentage of elongation, microhardness, and wear behavior, respectively. This implies that the synthesized composite may be used in nuclear applications successfully. The subsequent explanation was drawn from this investigative work: • The LM 25/B4C/Gr hybrid nanocomposite was successfully manufactured by employing the stir casting technique. For nuclear shielding applications, these composites were prepared with three different weight percentages of nanoparticle reinforcements in 2,4,6% Boron carbide and constant 4 wt.% graphite. • The microhardness values of the three-hybrid nanocomposite fabricated castings were determined to be 143.4VHN, 156.7VHN, and 169.2VHN, respectively. • The hybrid nano composite's microstructure revealed that the underlying LM 25 aluminum alloy matrix's finegrained, evenly dispersed nanoparticles of graphite and boron carbide were present.<br></br> • The microtensile test was carried out and it was found that the ultimate tensile strength, yield strength and percentage of elongation values are 281.35MPa, 296.52MPa, 308.76MPa, 269.43, 274.69, 293.51 and 3.4, 5.7, 7.8 respectively.<br></br> • Deformation caused the hybrid LM 25/B4C/Gr nanocomposite to fracture in ductile mode. Dimples and cavities are seen in the fracture because of the nanoparticle reinforcements and the matrix's tight connection.<br></br> • The wear loss of nanocomposite based on the input parameter applied load, sliding velocity and sliding distance values are 0.02456, 0.02189, 0.01854, 0.02892, 0.02586, 0.02315 and 0.02682, 0.02254, 0.02015 mm3/m, respectively.<br></br> • The LM 25 alloy's elemental analysis displays the aluminum alloy phase as the largest peak and the remaining elements as smaller peaks; also, the spectral analysis reveals the presence of boron (B), graphite (C), silicon, and ferrous in the aluminum alloy LM 25.<br></br> • Through worn surface FESEM investigation, it was shown that under sliding and high load situations, debris, delamination, and groove develop. Further rupture, fine, and continuous grooves were seen when low stress and sliding circumstances were applied to the LM 25/B4C/Gr and stir cast specimen. This result implies the presence of mild adhesive and delamination wear processes.</P>.

Ag-CsPbI3 nanocomposite structure in glasses boosts photoluminescence for efficient light emitting diodes

Nanocomposite structures based on perovskite nanocrystals (NCs) and metal nanostructures within transparent monolithic media hold promise for a wide range of applications in optoelectronics. However, the microstructure of such nanocomposites and the reason for enhanced emissions remain incompletely understood. In this work, we present the successful creation of Ag-CsPbI3 nanocomposite within a highly transparent borosilicate glass (Ag-CsPbI3 NCs@glass). We reveal that Ag and CsPbI3 NCs form after thermal treatment of the glass, either in the form of Ag-CsPbI3 heterostructures or of separate Ag and CsPbI3 NCs. Based on combined characterization of Mott-Schottky and steady-state photoluminescence (PL) of the products, we attribute the enhanced PL in the nanocomposite of Ag-CsPbI3 to the regulation of CsPbI3 lattice by Ag ions and/or the plasmonic effect of Ag NCs. Temperature-dependent time-resolved PL decay measurements suggest that Ag NCs could play an important role in the relaxation process of excited carriers by increasing the radiative recombination. Moreover, the Ag-CsPbI3 nanocomposite structure within the glass matrix curtails PL quenching caused by water molecules and high temperature. Using the Ag-CsPbI3 nanocomposite, we achieve high-performance white light-emitting diodes with a color rendering index of 83.9 and luminous efficiency of 58.07 lmW−1. This work elucidates the underlying mechanism on the enhanced PL in nanocomposites containing perovskite NCs and metal nanostructures, and aids in the rational design of glass-based perovskite nanocomposites for a diversity of optoelectronic applications.

Silicon carbide nanoparticles featured AZ63/BN alloy nanocomposite made by using liquid stir vacuum die cast: characteristics study

ABSTRACT With the unique class, the reinforcements play a precious role during the composite fabrication, expanding the specific properties. The novel research intensively enhances the micro-structural and mechanical behaviour of magnesium alloy (AZ63/3 wt% boron nitride) nanocomposite featured 2, 4, and 6 wt% of nano-size silicon carbide (SiC) particles via liquid state vacuum stir cast route. The exposure of SiC and BN on composite density, voids contribution, changes in AZ91D microstructure, impact toughness, hardness, and stress-strain individuality of AZ63 alloy nanocomposite is evaluated with ASTM policy. The composite composed with 3 wt% BN and 6 wt% SiC proved their identity. It showed the lower contribution of voids-free homogenous dispersion particle results in a maximum impact strength of 14.7J/mm2, hardness of 74HV, and superb tensile strength of 247MPa. This optimum behaviour will be recommended for automotive roof frame applications.

A 30-Year Review on Nanocomposites: Comprehensive Bibliometric Insights into Microstructural, Electrical, and Mechanical Properties Assisted by Artificial Intelligence.

From 1990 to 2024, this study presents a groundbreaking bibliometric and sentiment analysis of nanocomposite literature, distinguishing itself from existing reviews through its unique computational methodology. Developed by our research group, this novel approach systematically investigates the evolution of nanocomposites, focusing on microstructural characterization, electrical properties, and mechanical behaviors. By deploying advanced Boolean search strategies within the Scopus database, we achieve a meticulous extraction and in-depth exploration of thematic content, a methodological advancement in the field. Our analysis uniquely identifies critical trends and insights concerning nanocomposite microstructure, electrical attributes, and mechanical performance. The paper goes beyond traditional textual analytics and bibliometric evaluation, offering new interpretations of data and highlighting significant collaborative efforts and influential studies within the nanocomposite domain. Our findings uncover the evolution of research language, thematic shifts, and global contributions, providing a distinct and comprehensive view of the dynamic evolution of nanocomposite research. A critical component of this study is the "State-of-the-Art and Gaps Extracted from Results and Discussions" section, which delves into the latest advancements in nanocomposite research. This section details various nanocomposite types and their properties and introduces novel interpretations of their applications, especially in nanocomposite films. By tracing historical progress and identifying emerging trends, this analysis emphasizes the significance of collaboration and influential studies in molding the field. Moreover, the "Literature Review Guided by Artificial Intelligence" section showcases an innovative AI-guided approach to nanocomposite research, a first in this domain. Focusing on articles from 2023, selected based on citation frequency, this method offers a new perspective on the interplay between nanocomposites and their electrical properties. It highlights the composition, structure, and functionality of various systems, integrating recent findings for a comprehensive overview of current knowledge. The sentiment analysis, with an average score of 0.638771, reflects a positive trend in academic discourse and an increasing recognition of the potential of nanocomposites. Our bibliometric analysis, another methodological novelty, maps the intellectual domain, emphasizing pivotal research themes and the influence of crosslinking time on nanocomposite attributes. While acknowledging its limitations, this study exemplifies the indispensable role of our innovative computational tools in synthesizing and understanding the extensive body of nanocomposite literature. This work not only elucidates prevailing trends but also contributes a unique perspective and novel insights, enhancing our understanding of the nanocomposite research field.

Integrating uncertainty into deep learning models for enhanced prediction of nanocomposite materials’ mechanical properties

In this paper, we present a novel deep-learning framework that incorporates quantified uncertainty for predicting the mechanical properties of nanocomposite materials, specifically taking into account their morphology and composition. Due to the intricate microstructures of nanocomposites and their dynamic changes under diverse conditions, traditional methods, such as molecular dynamics simulations, often impose significant computational burdens. Our machine learning models, trained on comprehensive material datasets, provide a lower computational cost alternative, facilitating rapid exploration of design spaces and more reliable predictions. We employ both convolutional neural networks and feedforward neural networks for our predictions, training separate models for yield strength and ultimate tensile strength. Furthermore, we integrate uncertainty quantification into our models, thereby providing confidence intervals for our predictions and making them more reliable. This study paves the way for advancements in predicting the properties of nanocomposite materials and could potentially be expanded to cover a broad spectrum of materials in the future.

Microstructure and properties of aluminium matrix hybrid nanocomposite

ABSTRACT Aluminium metal matrix nanocomposites (MMNCs) reinforced with particulate have been in the limelight recently due to their improved tribological and mechanical properties such as stiffness, strength, impact resistance, wear resistance, etc. It is well known that carbon nanotube and silicon carbide nanomaterials are widely used as reinforcements in various types of metal or alloy matrix materials. However, hybrid metal matrix nanocomposites reinforced with more than one type nanomaterials are rarely reported in the literature. In this work, a novel aluminium matrix hybrid nanocomposite with carbon nanotube and nano SiC has been fabricated. Properties of hybrid nanocomposites are compared with nanocomposites reinforced with individual reinforcements. Vicker’s micro-hardness property of specimens was tested at 100 gmf load applied at 10 s dwell time. The hardness and compressive strength have increased 111% and 58%, respectively with the reinforcement of nanoparticles in the metal matrix. Dry wear property of specimens was carried out at 35, 40 and 45 N load with variable speeds viz. 500, 550 and 600 rpm. Wear resistance increases as the carbon reinforcement increases in the metal matrix. The wear mechanism of nanocomposite materials has been evaluated by using scanning electron microscopic analysis.

Enhancement of electromagnetic attenuation of network CNT-Carbon microsphere nanocomposites derived from phenolic resin

Carbon nanocomposites have attracted extensive attention due to their excellent electromagnetic attenuation (EMA) properties. Herein, carbon nanocomposites containing the carbon nanotube (CNT)-carbon microsphere (CS) network derived from phenolic resin are prepared, and their EMA properties are investigated. The results show that the microstructure of these carbon nanocomposites can be regulated by a catalyst to transform CSs into CNTs, which ultimately results in the networks forming a “resistor-capacitor” structure. As a result, the minimum reflection loss (RLmin) is −60.77 dB at 2.80 GHz, which is within the S-band, and the maximum effective absorption bandwidth (EAB) is 5.77 GHz. The excellent EMA properties can be attributed to the synergistic effect of heterogeneous interfacial and conduction networks, which induces abundant interfacial polarization and conduction loss. A new solution for achieving a wide absorption band for carbon and high electromagnetic wave attenuation in carbon nanocomposites is proposed.

Atomistically informed hierarchical modeling for revisiting the constituent structures from heredity and nano-micro mechanics of sheath-core carbon fiber.

To better understand the heterogeneous anisotropic nanocomposite features and provide reliable underlying constitutive parameters of carbon fiber for continuum-level simulations, hierarchical modeling approaches combining quantum chemistry, molecular dynamics, numerical and analytical micromechanics are employed for studying the structure-performance relationships of the precursor-inherited sheath-core carbon fiber layers. A robust debonding force field is derived from energy matching protocols, including bond dissociation enthalpy calculations and rigid-constraint potential energy surface scan. Logistic long range bond stretching curves with exponential parameters and shifted force vdW curves are designed to diminish energy perturbations. The pseudo-crystalline microstructure is proposed and validated using virtual wide angle X-ray diffraction patterns and bond-orientational order parameters. The distribution or alignment features of the nanocomposite microstructures are collected from quantum chemical topology analysis and normal vector extractions. Non-equilibrium tensile loading simulation predicts the decomposed strain energy contributions, principal-axis modulus, strength limit, localized stress, and fracture morphologies of the model. Finally, an atomistically-informed stiffness prediction model combining numerical homogenization and analytical self-consistent Eshelby-Mori-Tanaka-type effective mean field micromechanics theory is proposed, giving a successful estimation of the overall stiffness matrix of the sheath-core carbon fiber system. The hierarchical models in combination with the carbonization reaction template will help in providing efficient and feasible schemes for the synergistic process-performance control of distinct types of carbon fiber.

Evolution of the Microstructure of PP-LDHs Nanocomposites during Melt Compounding: A Simulation Approach.

In the context of polymer-based nanocomposites containing layered nanofillers, the achievement of good extents of dispersion and distribution of the embedded nanoparticles and, even more, the obtainment of intercalated and/or exfoliated structures through melt compounding still represents a persistent challenge, especially in the case of anionic layered double hydroxides (LDHs)-containing systems and non-polar polymeric matrices. In this work, a simulation approach is proposed to evaluate the influence of the processing conditions on the morphology of polypropylene (PP)-based nanocomposites containing organomodified LDHs. In particular, the effect of the screw rotation speed and the feed rate on the final microstructure of the materials formulated through melt compounding in a twin-screw extruder was assessed. The rheological and morphological characterizations demonstrated that a more homogeneous morphology was achieved when high levels of both exploited processing parameters are selected. The results coming from the simulation of the processing were used to establish some relationships between the flow parameters and the microstructure of the nanocomposites, demonstrating that low residence times coupled with high local shear rates are required to ensure the achievement of homogenous morphologies, likely involving the occurrence of intercalation phenomena.

Fabrication of predesigned 3D carbon based microstructures via two-photon vat photopolymerization and susceptor-assisted microwave post-processing

This study presents a fabrication strategy for 3D carbon microstructures using via two-photon vat photopolymerization (2p-VPP) and susceptor-assisted microwave pyrolysis (SMWP). Fabricating carbon-based electrode materials with miniaturized functional structures is pivotal for developing high-performance electrochemical microdevices. However, efficiently producing these structures in the submicron regime with desired materials is still challenging. To address this, a hybrid microfabrication strategy was developed, and 3D carbon-based microstructures with submicron resolution were successfully produced. A carbon nanotube nanocomposite photoresist (SCNT-PR1) with improved dispersibility was first prepared. After a comprehensive printability assessment, 3D microstructures with a resolution of 833 ± 54 nm were produced using 2p-VPP. Through SMWP, the microstructures were transformed into pyrolytic carbon (PyC) nanocomposite microstructures with retained geometrical features. SMWP was shown to produce PyC with a less disordered carbon atomic structure, thanks to the accelerated pyrolysis reaction under MW irradiation, when compared to pyrolysis using a conventional furnace. The resistivity was reduced by over 75% from 0.69 ± 0.13 Ω cm to 0.16 ± 0.01 Ω cm, and enhanced electrochemical performance was confirmed. The fabricated PyC nanocomposite showed a further 12% reduction in electrical resistivity and a 20% lower charge transfer resistance for the redox reaction when using SCNT-PR1 as the precursor. Overall, this hybrid fabrication strategy demonstrates the advantages of producing 3D carbon microstructures with precise control over the geometric features and enhancing electrical and electrochemical properties compared to the conventional pyrolysis method. Its potential could be extended to the fabrication of miniaturized electrochemical devices, including microelectronics and point-of-care devices.

Bimetallic MOFs/MXene derived CoNi@C@Ti3C2Tx/TiO2 nanocomposites for high-efficiency electromagnetic wave absorption

Constructing intricately designed multiple heterogeneous interfaces offers an effective strategy for exploring lightweight and efficient microwave absorbing materials (MAMs). Herein, the CoNi@C@Ti3C2Tx/TiO2 (CNCTT) nanocomposites with multiple heterogeneous interfaces were synthesized using the straightforward solvothermal method, electrostatic self-assembly, and subsequent heat treatment process, utilizing bimetallic CoNi-MOF-74@few-layered Ti3C2Tx MXene as the precursor. The modulation of composition, microstructure, and electromagnetic wave absorption (EMWA) properties of the CNCTT nanocomposites was comprehensively investigated by simply controlling the ratio of magnetic metal sources. Hierarchical porous structure simultaneously promotes interfacial polarization by quaternary CoNi/C/MXene/TiO2 interfaces, enhances magnetic loss by the CoNi nanoparticles coupling network, enlarges conduction loss by the graphite carbon layer/MXene/TiO2 triple-network, and optimizes impedance matching with the synergistic effect of dielectric loss and magnetic loss. Significantly, it is observed that the C3N3CTT nanocomposite, with the molar ratio of Co:Ni is 3:3 and a filler loading of 30 wt%, demonstrates an impressive minimum reflection loss (RLmin) of −70.26 dB at 15.92 GHz and an effective absorbing bandwidth (EAB, RL < −10 dB) of 4.19 GHz with an absorption layer thickness of 1.7 mm. Furthermore, the RLmin remains notable −40.50 dB with an expanded EAB of 5.17 GHz at a thickness of 1.8 mm. This endeavor can provide significant insights into the potential applications of MOF-derived composites in the realm of efficient electromagnetic wave absorption.

Unleashing multi-scale mechanical enhancement in NiTi shape memory alloy via annular intra-laser deposition with homogenized Ti2Ni nanoprecipitates

Additive manufacturing (AM) of composition-sensitive NiTi shape memory alloys (SMAs) is hindered by uncontrollable non-equilibrium microstructures, leading to functional performance degradation and limitations in high-throughput net-shaping applications. To address these challenges, we propose a novel approach combining annular intra-laser directed energy deposition (AIL-DED) with a tailored gradient post-treatment process. This enables the fabrication of nanocomposite microstructures in NiTi SMAs with precise control over the homogenization of Ti2Ni nanoprecipitates. In-situ monitoring and characterization of thermal history, microstrain, and constitutional phases, were utilized to uncover the relationship between multi-scale structural features and mechanical responses. The interplay between laser reflectivity, energy input, and lattice thermal vibrations affects forming quality in AIL-DED. Dynamic temperature variations were studied before reaching thermal equilibrium, revealing insights into thermal and mechanical interactions during the process. These findings contribute to understanding challenges in fabricating high-quality NiTi SMAs. Examining phase transformation behavior and its correlation with processing parameters deepens understanding of microstructural evolution and provides insights for tailoring material properties. The stress relaxation and dislocation evacuation at elevated temperatures caused the expansion of lattice and interplanar spacing in the age-treated SMA's B2 matrix phase, exhibiting a stable two-step phase transformation behavior (B19′↔R↔B2). AIL-DED combined with two-stage heat treatment strategy demonstrated enhanced homogeneity of non-equilibrium microstructures, resulting in the formation of high-density, well-dispersed Ti2Ni nanoprecipitates, with a semi-coherent interface to B2 matrix. The combination of load-bearing strengthening through well-dispersed Ti2Ni nanoprecipitates and Orowan strengthening at the semi-coherent interface yielded simultaneous enhancements in nanohardness, ultimate compressive strength, compressive fracture strain, and deformation recovery, following the AIL-DED combined with two-stage heat treatment process. The fracture mechanism transitioned from a mixture of brittle-ductile behavior to predominantly ductile characteristics. This study provides valuable insights that advance additive manufacturing and enhance the functional performance of SMAs in critical applications.

3D Printing of Bone Scaffolds Based on Alginate/Gelatin Hydrogel Ink Containing Bioactive Glass 45S5 and ZIF‐8 Nanoparticles with Sustained Drug‐Release Capability

Herein, 3D printing coupled with drug‐release systems introduces many advantages to bone‐regenerative medicine. In this research, hydrogel‐based nanocomposite inks comprising alginate/gelatin (Alg/Gel) matrix supplemented with mesoporous bioactive glass (MBG) and zeolite‐imidazole framework‐8 (ZIF‐8) nanoparticles are presented. A fixed wt% of mixed nanoparticles at MBG/ZIF weight ratios of 85:15 and 70:30 is added to Alg/Gel to prepare nanocomposite inks. All inks have shear‐thinning behavior, facilitating scaffolds’ 3D printing via extrusion. Scaffolds’ 3D spatial and nanocomposite microstructures are confirmed using field‐emission scanning electron microscope and energy‐dispersive X‐ray (FESEM/EDX) and Fourier transform infrared (FT‐IR). Shear punch testing indicates an enhanced shear strength of 85:15 samples in both dry (9.49 ± 0.23 MPa) and wet conditions (1.19 ± 0.16 MPa). After 1 month, nanocomposite scaffolds have a higher degradation rate (65%) than Alg/Gel (50%) in phosphate‐buffered saline. In vitro drug‐release study using UV–visible spectrophotometry exhibits a similar prolonged release profile for 85:15 and 70:30 nanocomposites compared to Alg/Gel. Due to its better mechanical performance, 85:15 is used for bioactivity and cellular tests. MBG provides bioactivity in simulated body fluid by the rapid development of hydroxyapatite validated by FESEM/EDX, XRD, and FT‐IR. Nanocomposite scaffolds exhibit significantly higher MG‐63 cell viability (&gt;90%) than Alg/Gel. Finally, these scaffolds provide a potential additive‐manufacturing solution to bone tissue regeneration.

Effect of silicon nitride nanoparticles on the microstructure, phase, hardness and wear properties of NiCrAlY-based nanocomposite

ABSTRACT Despite the significant oxidation resistance of NiCrAlY alloy, one of the disadvantages of this alloy is its softness and poor mechanical properties, and low wear resistance. Therefore, in this study, silicon nitride nanoparticles have been used to improve the hardness and wear resistance of the NiCrAlY alloy. The present research has examined the effect of different amounts of Si3N4 nanoparticles (1, 3, and 5 wt.%) on the structure and mechanical properties of NiCrAlY alloy. The samples were characterised by scanning electron microscopy, X-ray diffraction, and Vickers microhardness device. Initially, Si3N4 powders with 1, 3, and 5 wt% were mixed with NiCrAlY powder in a mechanical mill. Next, the powdered mixtures underwent spark plasma sintering (SPS) operations at 1100 °C for 6 min. The results of microhardness measurements showed that adding 1% Si3N4 to NiCrAlY caused the elevation of the hardness from 418 to 614 HV. Further, the sample indicated a wear rate of 1.42 × 10−5 (m3/N.m) at room temperature, under a loading force of 9.8 N, and a sliding length of 500 m. However, with an increase in the weight percentage of Si3N4 in the sample from 1 to 5 wt%, the hardness diminished from 614 to 543 HV.

Studying the relationship between microstructure and properties of polylactic acid/styrene-ethylene butyl-styrene blend reinforced by graphene

The main purpose of this study was to investigate the relationship between microstructure and mechanical performance of polylactic acid when mixed with styrene-ethylene butylene-styrene copolymer and also graphene nanoplatelets. For this purpose, a series of neat polymer blends were first prepared with varying mixing ratios through a one-step melt mixing technique. Subsequently, the effect of various loadings of graphene nanoplatelets on the best mixing ratio (optimal composition) of the binary blend was investigated. To understand the different performances of various nanocomposites, the correlation of mechanical, rheological, and microstructural properties was thoroughly investigated using X-ray diffraction, scanning electron microscopy, linear viscoelastic behavior, tensile testing, and impact strength analyses. Furthermore, the influence of the mixing sequence of nanocomposites preparation on the microstructure and mechanical performance of nanocomposites was studied. Results demonstrated that the incorporation of graphene nanoplatelets as well as mixing sequence has a substantial effect on the final properties of prepared nanocomposites which was deeply discussed.

Mechanical Characterization of AA357 Metal Matrix Composite with Reinforcement of Si3N4

Abstract The engineering sector researchers are always searching for new materials for their challenging applications. The aluminum alloy (AA) 357 plays a critical role in applications like automotive and aerospace because of its exceptional characteristics such as toughness, fatigue resistance, and more importantly strength-to-weight ratio, but it suffers from poor wear resistance. However, the research community is looking for enhancement in wear resistance at various loads. This research deals with AA357-Si3N4 nanocomposites fabricated through the induction stir casting method and evaluation of properties in comparison with AA357 matrix. The Si3N4 nanoparticulates were selected as reinforcement and added 0.5 to 3.0 wt.% in the steps of 0.5 wt.%. The influence of Si3N4 nano reinforcement content on hardness, strength, and wear resistance of AA357-Si3N4 nanocomposites investigative work was conducted as per ASTM standards. The studies of microstructures of AA357-Si3N4 nanocomposites were performed using an optical microscope to analyze grain structure and a scanning electron microscope (SEM) to examine particle distribution. The density, hardness, and ultimate tensile strength (UTS), in addition to morphological studies of fractured surfaces and energy dispersive spectroscopy for nanocomposites elemental study. As per ASTM G99, Standard Test Method for Wear Testing with a Pin-on-Disk Apparatus, standards, pin-on-disc equipment was used to examine tribological properties of AA357-Si3N4 nanocomposites and SEM pictures of worn nanocomposites surfaces analyzed extensively. By going through the experimental outcomes, it is realized that with increase in nano reinforcement in matrix AA357, the properties such as density, resistance to indentation/hardness, and UTS increased at the expense of percentage elongation. The pin-on-disc tribometer experimental results indicate that the fabricated AA357-Si3N4 nanocomposites have higher wear resistance.

Optimizations of performance of cellulose acetate modified by ZnSnO3/ZnO nanocomposites: electrical, dynamic mechanical analysis, and antibacterial activity

In this work, ZnSnO3/ZnO/cellulose acetate nanocomposites have been efficiently fabricated by simple wet chemical co-precipitation and drop casting techniques. The study characterized the nanocomposite's microstructure, morphology, dielectric and impedance spectra, dynamic mechanical analyses, and antibacterial performance. The XRD results reveal the production of composite materials, including well-split materials of nanocrystalline nature, from both constitutive organic and non-organic materials. With the addition of nanoparticles to the cellulose acetate, the real components of electrical conductivity, permittivity, and impedance behaviors exhibit improved performances as a function of frequency dependence. The results of the dynamic mechanical analysis (DMA) showed that the nanocomposite has a significant impact on the DMA parameters at Tg (storage modulus, loss modulus, loss tangent, stiffness, and viscosity modulus) by enhancing interfacial adhesion and optimizing the stress transition demand and power dissipation between the CAmatrix and nanoparticles. Moreover, the antibacterial activity of nanocomposites films is more effective against E. coli (G-ve) bacteria with a relatively wide diameter than against S.aureus (G+ve) bacteria. This ZS/ZO/CA matrix, which is supported by ZS/ZO nanostructures, is intended to be structural mechanical elements in structural engineering, electrochemical solid state systems, and antibacterial.

Effect of Jet Speed on the Microstructure and Performances of Ni-TiN Nanocomposites Prepared via Jet Pulse Electrodeposition

Effect of Jet Speed on the Microstructure and Performances of Ni-TiN Nanocomposites Prepared via Jet Pulse Electrodeposition

Application of rheology as a tool to estimate the mixing quality of elastomeric nanocomposites and comparing with small-angle X-ray scattering microstructural study

Finding a relation between microstructure and properties of nanocomposites is challenging for engineers to control properties of polymeric systems by controlling their microstructure or to estimate their microstructure parameters by studying their properties. Since rheological properties can be obtained in stress or strain modes, sweep of temperatures, sweep of frequencies, amplitudes of applied stress or strains sweep and over the time, creating a relationship between rheological properties and microstructure of nanocomposites has a higher practical freedom. Also, rheological properties are highly affected by mixing quality, which is defined microstructure parameters of systems, so rheology can be applied as a tool to estimate the mixing quality of polymeric systems. Therefore, the present study aims to present the structural model for the rheological behavior of nanocomposites were produced under different mixing conditions and establish the relationship between rheological properties and microstructure of these nanocomposites and evaluate the presented structure with Small-angle X-ray scattering data. Thus, elastomeric nanocomposites were produced at different mixing speeds and times. The results indicated at the lower mixing intensity the agglomerates of nanoparticles are first distributed in the rubber system by increasing the time and speed of mixing so at those mixing condition rheological properties decreased. Finally at the higher mixing intensity the aggregates of these particles start to break so the rheological properties increased. Based on the rheological properties, distributing of particles reduces the rheological properties of nanocomposites, while breaking aggregates increases the rheological properties.