Nano ZrO2 Research Articles

Chemical and Green Synthesis, Characterization, Electrical and Antimicrobial Activity of ZrO2 Nanoparticles

ZrO2 nanoparticles were successfully synthesized using a chemical and green synthesis method. Their structural, morphological, optical, anti microbial and electrochemical properties were characterized. The green and chemical synthesis of ZrO2 was achieved by using the ethanolic extract and NaOH as reagents. XRD analysis confirmed the ZrO2 nanoparticles' tetragonal crystal phase. The surface morphological properties under the phases of nucleation, growth and aggregation as well as elementary composition were confirmed by SEM and EDS. The Fourier Transform Infra Red (FTIR) analysis was used to investigate into the functional groups that were present in the molecules of the synthesized nanomaterials. The presence of zirconium oxide nanoparticles with an optical band gap value between 4.73 and 5.48 eV was confirmed by the absorption spectra at 226-232 nm Antimicrobial studies showed that ZrO2 nanoparticles had bactericidal activity at a dose of 10 g/mL against Proteus vulgaris, Eschericia coli, Pseudomonas aeruginosa, Enterococcus faecalis and Staphylococcus aureus. The overall results of this study showed that ZrO2 NPs with excellent bioremediation and antibacterial characteristics were formed. The electrochemical behavior of both ZrO2 nano particles was examined using cyclic voltammetry studies were observed. The maximum enhanced specific capacitance value at a 10 mV/s scan rate.

Al2O3 enhanced bi-phase high-entropy ceramic composites

One limitation of high-entropy ceramics is the low toughness that could hinder their implementations in the relevant industries despite the diverse potential applications. This challenge is increasingly attempted in recent years with high-entropy ceramic composites which consisted of high-entropy ceramic matrix and secondary phase. A suitable secondary phase candidate is Al2O3 which to-date has not been reported for such ceramic composites. In this work, bi-phase high-entropy ceramic composites of cubic fluorite oxide matrix and Al2O3 secondary phase were in situ synthesized from HfO2, ZrO2, CeO2, CaO and Al2O3 nano powders via solid-state reaction method. Variation of thermal and mechanical properties of the composites with Al ratio was due to the combined effects of the inherent properties of Al2O3, concentrations of grain boundary and of oxygen vacancies. The high-entropy ceramic composites enhanced by Al2O3 were also compared with yttria-stabilised zirconia for potential application as thermal barrier coating material.

Analysis and optimization of machining parameters of AZ91 alloy nanocomposite with the Influences of nano ZrO2 through vacuum diecast process

The magnesium alloy composite is a vital material for automotive applications due to its features like high stiffness, superior damping resistance, high strength, and lightweight. Here, the motto of research is to establish the AZ91 alloy nanocomposite with the exposures of 0, 1, 3, and 5 volume percentages (vol%) of nano zirconium dioxide (ZrO2) particles (50nm) through fluid stir metallurgy route associated with 1x105 Pa vacuum die cast process. Exposures on structural morphology, hardness, and impact toughness of composite are analyzed and identified as the nano AZ91 alloy composite enclosed with 5vol% is homogenous particle dispersion, enhanced hardness (97.6HV), and optimum toughness of 21.2J/mm2. However, composite faces machining difficulties due to the hard abrasive particles with higher hardness, resulting in tool wear. This experiment predicts the optimum mill parameters during the end mill operation of magnesium alloy nanocomposite (AZ91/5vol%) by using a tungsten carbide coated end mill cutter to attain the maximum metal removal rate with low surface roughness and tool wear analyzed via the general linear model (GLM) ANOVA approach. The input conditions for end milling operation vary, like feed rate (0.1 -0.4mm/rev), depth of cut (0.05 -0.2mm), and spindle speed (250-1000rpm). During the ANOVA GLM approach, the L16 design experiment is fixed for further interaction analysis. The results predicted by the depth to cut and feed rate were dominant and played a major role in deciding the tool wear, surface roughness, and MRR.

Investigating the effect of zirconium dioxide micro and nano particles on the mechanical characteristics of Al-7075 alloy

ABSTRACT The study investigates the influence of zirconium dioxide (ZrO2) particles on the mechanical properties of Al7075 alloy and aims to assess the potential for tailored compositions to meet specific engineering requirements, particularly in aerospace applications. Al7075-ZrO2 composite was fabricated with varying percentages of micro (µ) ZrO2 (1%, 2%, and 3%) and nano ZrO2 (0.17%, 0.34%, and 0.51%) particles using the stir casting technique. Mechanical testing was conducted to evaluate the peak stress, load, and yield strength of the resulting Al7075-ZrO2 composites. Experimental findings reveal that the highest peak stress and load were achieved at 0.51% nano ZrO2 content, indicating a reinforcement effect. Moreover, the composite with 0.34% nano ZrO2 exhibited 59% increased peak stress of 153 MPa and 24% decreased strain 3.7% compared 125 MPa and 4.9% for pure Al7075. Al7075-µZrO2 composite has shown 125 MPa of peak stress and 2.9% maximum strain. These properties highlight the potential of Al7075-ZrO2 composite for applications requiring high resistance to tensile failure. Incorporating nano ZrO2 particles positively impact the load-bearing capacity and strength of Al7075 alloy matrix. Specifically, compositions with tailored ZrO2 content percentages demonstrate the potential for meeting the stringent requirements of aerospace applications.

Response surface methodology optimization of characteristics of biodiesel powered diesel engine and its effective integration to autonomous microgrid

An optimum diesel engine load condition with higher thermal efficiency and energy management has been the foremost challenge in the renewable energy research field. Modern trends involve nano additives for obtaining high performing biodiesel blends. Considering the above-mentioned factors, an experimental study along with statistical analysis has been performed with variation of compression ratio (16, 17.5 & 18), ZrO2 nano additive (50, 100 & 150 ppm) and load (50, 75 & 100 %). The optimization was accomplished by diminishing the BSFC, NOx, HC, CO, and increasing the BTE, CO2 using the approach of desirability. From the obtained results, the optimum operating conditions of the engine were found to be 75 % load, 18:1 compression ratio, and 150 ppm ZrO2 nano additive. The actual values at optimized conditions are obtained as BSFC (0.27 kg/kWh), BTE (33.37 %), CO (0.71 %), CO2 (8.69 %), NOx (1270 ppm), HC (62 %) and Smoke (25.20 %) with error less than 5 %. It has been observed that the BSFC of the proposed biodiesel-diesel blend is lower than that of pure diesel in all levels of power output. The biodiesel fuelled diesel engine is integrated as backup power in autonomous microgrid with main power as solar PV system operated at MPPT mode. A hybrid power system based on solar PV and biodiesel generator set up is the better alternative to emission-intensive fossil fuel and intermittent renewable.

Effect of titanium dioxide and zirconium dioxide nanoparticle incorporation on the thermal conductivity of heat-activated polymethylmethacrylate denture base resins: An in vitro experimental study.

The aim is to determine thermal conduction by heat-activated polymethylmethacrylate (PMMA) infiltrated with 1 weight% Titanium Dioxide (TiO2) and 1 weight% Zirconium Dioxide (ZrO2) nanoparticles and to compare with that of conventional PMMA. In vitro experimental study. Eighteen disc shaped specimens with a thickness of 5 mm and diameter of 50 mm, were fabricated and grouped according to the material used: Group B1 (resin infiltrated with 1 weight% TiO2), Group B2 (resin infiltrated with 1 weight% ZrO2), and Control Group B3 (heat-activated conventional PMMA resin). Disc-shaped specimens were analyzed for thermal conductivity using "modified guarded hot plate apparatus" in the thermal lab of the Indian Space Research Organisation. One-way ANOVA followed by Tukey's post hoc test was used to compare the arithmetic means of all three groups. A statistically significant difference was noted among all three groups. Group B2 had the maximum thermal conductivity, followed by Group B1. Thermal conductivity was the least for Group B3. A post hoc comparison revealed that the difference was significant between Group B2 and Group B3. Nano ZrO2 addition in PMMA increased its thermal conductivity. There is evidence that it improves its mechanical properties as well. Hence, Nano ZrO2 addition in PMMA is highly recommended. Nano TiO2 addition in PMMA did not provide any significant advantage in terms of thermal conductivity, but its addition in PMMA is justified because of its mechanical and antimicrobial properties.

Microstructure, hardness, electrical, and thermal conductivity of SZCN solder reinforced with TiO2 and ZrO2 nanoparticles fabricated by powder metallurgy method

The microstructure and characterization of Sn–Zn–Cu–Ni (SZCN) solder alloy reinforced with TiO2 and ZrO2 nanoparticles (NPs) synthesized by powder metallurgy were investigated. Sn, Zn, Cu and Ni metallic powders were mixed mechanical by 10:1 ball to powder ratio with 300 rpm speed for 2 h. Then 0.5 wt% from nano ZrO2 or TiO2 was mixed by the same parameters with the mixed metal powder. The morphologies and microstructures development during the fabrication process was investigated by X-ray diffractometer (XRD), optical microscope (OM), and scanning electron microscope (SEM) with energy dispersive X-ray spectrometry (EDX). The results reveal an improved distribution of TiO2 or ZrO2 NPs in the SZCN matrix solder, which resulted in an improvement in its density. The analyses of microstructural demonstrated that the addition of TiO2 or ZrO2 NPs to SZCN solder results in the grain refinement of the β-Sn phase, besides the formation of Ni3Sn IMC with small size and uniform distribution. The microhardness was enhanced as a result of the addition of TiO2 or ZrO2 NPs. The experimental results showed that the SZCN-ZrO2 composite solder had the greatest hardness and stress exponent values due to its effectiveness in suppressing the growth of β-Sn grains and the pile-up of dislocations. Both the electrical and thermal conductivities were improved by incorporating TiO2 NPs compared to other solders.

Corrosion Protection Performance of PACC and PACC-Metal Oxides Nanocomposites Electropolymerized Coating of Low Carbon Steel

In the current study, a novel conductive polymer poly 6-((4 acetylphenyl) carbamoyl) cyclohex-3-ene-1-carboxylic acid (PACC) was created by polymerized 6-((4 acetylphenyl) carbamoyl) cyclohex-3-ene-1-carboxylic acid (ACC) monomer using the electropolymerization process. The resulting polymer was characterized using Fourier Transform Infrared Spectroscopy (FTIR). The ability of this polymer to protect the alloy from corrosion was studied at temperatures ranging between 298 and 328 K. The ability of these coatings to stop corrosion on the surface was assessed by measuring the corrosion potential (Ecorr) and the corrosion current (icorr) using a potentiostat. Adding nanoscale metal oxides (zirconium dioxide (ZrO2) and magnesium oxides (MgO)) enhanced the efficiency of this polymeric coating. The protection efficiency of the polymer alone was 77.5%; this efficiency increased to 85.0% and 99.7% in the presence of nano ZrO2 and MgO, respectively. Kinetic and thermodynamic parameters (Ea, H, and S) were calculated for uncoated and coated LCS. An atomic force microscope (AFM) studied the coating surface morphology. Electrochemical impedance spectroscopy (EIS) was used to evaluate the coating resistance.

Eco-friendly guar gum composites as solid-state electrolytes

Solid-state Guar gum electrolytes were prepared through the solution casting technique, employing a composition of 70 % Guar gum and 30 % ZnSO4·7H2O(GZ3). Different weight concentrations of nano ZrO2 (2.5 %, 5 %, 7.5 %, and 10 %) were introduced into the present Guar gum electrolytes. As prepared ZrO2 nanofiller substituted Guar gum electrolytes were examined by XRD, FTIR, DSC, and SEM to evaluate the amorphous characteristics, complexation, glass transition temperature, and surface morphology, respectively. Electrochemical impedance was utilized to examine the frequency-dependent ionic conductivity and dielectric properties of prepared ZrO2 nanofiller-substituted Guar gum electrolytes. At a temperature of 100 °C, the Guar gum electrolyte with10 % Nano ZrO2 exhibited an ionic conductivity of 3.19 × 10−3 S/cm, whereas, at room temperature (RT), it recorded a value of 1.09 × 10−3 S/cm. The activation energy for these electrolytes varied within the range of 0.26 eV–0.39 eV. Furthermore, an investigation of the frequency-dependent dielectric properties revealed a significant tail in the low-frequency region and the presence of space charge polarization within the electrolyte. The study also explored the relaxation time and hopping mechanism through dielectric modulus parameters. Moreover, a flexible Zn-based electrochemical cell was fabricated using a formulation comprising 70 % Guar gum, 30 % Zinc salt, and 10 % Nano ZrO2. The outcomes revealed an open circuit voltage of 0.82V, a discharge rate of 0.04C sustained over 25 h, with an average current discharge rate of approximately 1.4 mA per hour, resulting in an electrochemical-specific capacity of around 45mAh/g. Additionally, a solar cell device was fabricated using Guar gum electrolytes, and the photovoltaic parameters were computed. The maximum overall power conversion efficiency (ƞ) reached 4.79, with short-circuit photocurrent density (Jsc) at 9.66 mA/cm2, open-circuit voltage (Voc) at 725 mV, and fill factor (FF) at 0.65.

Understanding the effect of non-carbon-based nanoinclusions on chloride penetration resistance and chloride binding capacity of ultra-high performance cementitious composite

Ultra-high performance cementitious composite (UHPCC) with high durability has been widely employed to prevent the chloride corrosion of reinforced concrete structures exposed to the marine environment. Adding nanoinclusions is expected to fundamentally eliminate the defects (i.e., pores and microcracks) caused by the formulation principle of UHPCC, thereby reducing connected pathways for chloride diffusion. Furthermore, the diffusion resistance of chloride ions largely depends on the chloride binding capacity (CBC) of cement-based composites. Regrettably, the effects of non-carbon-based nanoinclusions on chloride penetration resistance (CPR) and CBC of UHPCC still lack comparison and analysis. This study investigated the effect of non-carbon-based nanoinclusions on the CPR and CBC as well as microstructures of UHPCC, including nano-SiO2 (NS), nano-ZrO2 (NZ), nano-TiO2 (NT), and boron nitride (BN). Correlation between pore structure parameters and CPR of composites was established based on the grey system theory. The results of rapid chloride migration (RCM) tests indicate that due to the incorporation of 1 % NS, 3 % SiO2-coated NT, 1 % NZ, and 0.5 % BN, the CPR of UHPCC is improved by 89.6 %, 66.5 %, 87.5 %, and 73.6 %, respectively. The results of the grey correlation analysis highlight the critical role of harmless and less harmful pores with a diameter below 50 nm in preventing the diffusion of chloride ions. The modifying mechanisms of nanoinclusions can be attributed to the nano-core effects, contributing to reducing chloride diffusion pathways and increasing disconnectivity and tortuosity of the pathways. Firstly, nanoinclusions can reduce pores and microcracks, improving the homogeneity of pore size distribution and inhibiting the growth of CH crystals, thus enhancing the compactness of the cement paste matrix. Secondly, nanoinclusions enriched in the interfacial transition zone (ITZ) can improve the homogeneity of ITZ by optimizing the Ca/Si ratios of C–S–H gels and improving the interfacial bond between cement paste and aggregate. Additionally, Langmuir and Freundlich isotherms can accurately describe the CBC of composites. Only NS among nanoinclusions can significantly improve the CBC of UHPCC. This can be attributed to the involvement of pozzolanic NS in cement hydration, promoting the formation of C–S–H gels for physically adsorbing chloride ions while increasing the diffusion resistance of chloride ions in the pathways.

Sustainable synthesis of levulinic acid using waste derived silica-alumina-hydroxyapatite supported nano ZrO2 photo-acidic catalyst under synergistic UV-FIR irradiations

A novel nano-photocatalyst has been prepared using hydroxyapatite (HAp) derived from waste fish scale and fly ash-derived aluminosilicate (SiO2-Al2O3) grafted with zirconium oxide (ZrO2) active sites by innovative photo-hydrothermal protocol. The physiochemical properties of the prepared photocatalyst have been characterized by different analyses like TGA, XRD, FTIR, XPS, UV–VIS–NIR, BET, NH3-TPD, HRTEM, and DLS. The optimal catalyst has a zirconium loading of 20 wt% and has a low bandgap energy of 2.15 eV as confirmed by UV–VIS–NIR spectroscopy. The optimal catalyst also depicted a high acidity of 1.52 mmol NH3/g and a specific surface area of 62.872 m²/g. Owing to the high acidity, specific surface area, and low band gap energy the photocatalyst has led to achieving an elevated yield of 76.6% levulinic acid (LA) from glucose in hybrid irradiation reactor (HIR) deploying UV and FIR radiations at appreciably low temperature and reaction time of 115 ℃ and 2 h respectively. Under the same reaction conditions, the conventionally heated reactor (CHR) gave a very low yield of 23.7%. Individual radiation effects on LA yield evinced the synergistic advantageous effect of the hybrid irradiation technique. The catalyst reusability and regenerative study confirmed the high stability of the prepared catalyst. Also, a comparative LCA study has been conducted between HIR and CHR systems which revealed that HIR was more environmentally sustainable than CHR. HIR -based process demonstrated a reduction in 59% global warming potential, 70.66% forest resource scarcity, and 65% lower terrestrial ecotoxicity while being 120% more energy efficient than CHR-based reaction making HIR more environmentally sustainable as well as economically feasible.

Attenuation properties of poly methyl methacrylate reinforced with micro/nano ZrO2 as gamma-ray shields

This research aimed to examine the radiation shielding properties of unique polymer composites for medical and non-medical applications. For this purpose, polymer composites, based on poly methyl methacrylate (PMMA) as a matrix, were prepared and reinforced with micro- and nanoparticles of ZrO2 fillers at a loading of 15%, 30%, and 45% by weight. Using the high purity germanium (HPGe) detector, the suggested polymer composites’ shielding characteristics were assessed for various radioactive sources. The experimental values of the mass attenuation coefficients (MAC) of the produced composites agreed closely with those obtained theoretically from the XCOM database. Different shielding parameters were estimated at a broad range of photon energies, including the linear attenuation coefficient (μ), tenth value layer (TVL), half value layer (HVL), mean free path (MFP), effective electron density (Neff), effective atomic number (Zeff), and equivalent atomic number (Zeq), as well as exposure buildup factor (EBF) and energy absorption buildup factor (EABF) to provide more shielding information about the penetration of γ-rays into the chosen composites. The results showed that increasing the content of micro and nano ZrO2 particles in the PMMA matrix increases μ values and decreases HVL, TVL, and MFP values. P-45nZ sample with 45 wt% of ZrO2 nanoparticles had the highest μ values, which varied between 2.6546 and 0.0991 cm−1 as γ-ray photon energy increased from 0.0595 to 1.408 MeV, respectively. Furthermore, the highest relative increase rate in μ values between nano and micro composites was 17.84%, achieved for the P-45nZ sample at 59.53 keV. These findings demonstrated that ZrO2 nanoparticles shield radiation more effectively than micro ZrO2 even at the same photon energy and filler wt%. Thus, the proposed nano ZrO2/PMMA composites can be used as effective shielding materials to lessen the transmitted radiation dose in radiation facilities.

Optimization of stir casting parameters for the tensile behavior of nano Al2O3 and ZrO2 reinforced Al-Mg-Si alloy metal composites

Stir casting is a frequently used method in the metallurgical process of casting aluminium composites. The microstructure and performance of the composites are influenced by the stirring casting parameters. The majority of research conducted in this area focused on producing composites using stir casting parameters that were predetermined, without utilizing an optimization method. This work aims to optimize the stir casting parameters for the manufacturing of Al-Mg-Si (Al6061) alloy reinforced with hybrid nano Al2O3 and nano ZrO2 in order to enhance its performance. The Taguchi optimization technique was employed to analyze the important effects of stir casting parameters on the ultimate tensile strength of a hybrid metal matrix composite. The composites were produced by the ultrasonic aided stir casting method, employing a set of process parameters determined by the Taguchi L16 orthogonal array. The S/N (Signal to Noise ratio) and Regression model were utilized to determine the optimal values and assess the influence of process parameters on the tensile qualities. The Minitab 21 software was utilized to perform simultaneous optimization of the attributes. The findings indicated that the composition of the nano reinforcement, stirring temperature, stirring speed, and stirring time all had a substantial impact on improving the UTS (Ultimate Tensile Strength) of the material.

Effect of nano hybrid additives on low velocity impact responses of aramid composite plates: example of CNT and ZrO2

Aramid reinforced composites are advanced materials that are widely used in many industrial applications thanks to their combination of high strength and lightness. Nano additives are of great importance for improving the mechanical properties of aramid reinforced composites and reducing costs. In this paper, multi-walled Carbon Nanotube (CNT) and Zirconia (ZrO2) nano hybrid additives were used to determine the effect on the mechanical characterization of aramid composite plates. Therefore, low velocity impact responses of aramid fiber reinforced composites were investigated by adding ZrO2 and CNT nano hybrid additives to the Polives 701 polymer vinylester resin matrix. Low velocity impact tests were carried out at 10 J and 15 J. As a result of the experiments, the effects of nano hybrid additives on the impact absorption properties of aramid composite plates were determined. By determining the maximum force, displacement and time values, the effect of CNT and ZrO2 nano hybrid additives on the impact resistance of the composite plates was analyzed. In addition, it contributed to the development of composite materials used in industrial applications by providing information on increasing the performance of composite materials by using nano additives. As a result of this study, it was determined that the strength of the composite material increased proportionally when the CNT additive was used, and the material became embrittled when the ZrO2 additive was used.

Synthesis and characterization of PMMA-grafted-ZrO2 hybrid nanoparticles

In this study, we reported a facile synthesis and the characterization of PMMA-grafted ZrO2 hybrid nanoparticles from original ZrO2 (oZrO2) nanoparticles. The synthesis process included of three steps: (i) modification of nano ZrO2 with a vinyl silane agent, (ii) graft copolymerization of methyl methacrylate (MMA) monomers and modified ZrO2 (mZrO2) nanoparticles, and (iii) extraction of homo PMMA to obtain the final product of PMMA-g-ZrO2 (gZrO2) nanoparticles. Fourier transform infrared (FTIR) spectra and thermogravimetric analysis (TGA) of mZrO2, oZrO2, and gZrO2 indicated that the silane coupling agent was grafted onto oZrO2 nanoparticles. FTIR spectra of gZrO2 indicated PMMA had been successfully grafted onto the surface of ZrO2 nanoparticles. Using TGA method, the PMMA grafting content onto ZrO2 nanoparticles was evaluated as 9.03 wt.%. The electron microscopy (SEM) images of gZrO2, mZrO2, and oZrO2 indicated that their primary particle size and shape were almost unchanged after modification processes, their particle size was in the range from 50 nm to 140 nm. XRD analysis showed the monoclinic crystalline structure of three kinds of ZrO2 nanoparticles (nanocrystals). The organic gZrO2 nanoparticles can be a better candidate as an opacifier additive for polymer nanocomposites or acrylic bone cement.

Enhanced Energy Storage Properties of Polypropylene/Glycidyl Methacrylate Grafted Polypropylene/Nano-ZrO2 Ternary System

Extensive research has focused on enhancing the energy storage density of polypropylene (PP) to meet the demands of high-power and compact electronic devices and electrical systems. However, there is a lack of studies addressing the delicate balance between energy storage density and dielectric loss. Dielectric loss can lead to excessive heat generation, posing a threat to the operation of energy storage capacitors. In this study, PP grafted with glycidyl methacrylate (GMA) was used as a compatibilizer and incorporated into a PP/nano ZrO2 blend to form a ternary system of PP/nano ZrO2/PP grafted GMA. A comparative study was conducted to analyze the effects of GMA grafting and individual doping of nano ZrO2 on the dielectric performance of PP. The results demonstrate that the ternary system not only ensures a high breakdown voltage (382.29 MV/m) but also possesses a high dielectric constant (2.67), thereby achieving an energy storage density of 1.7275 J/cm3 while maintaining low dielectric loss. Furthermore, grafting GMA introduces a significant number of deep traps, a phenomenon substantiated by the results of thermal stimulated depolarization current tests and molecular simulation calculations. However, the ternary system partially avoids the introduction of excessive deep traps associated with GMA grafting. This ternary system exhibits excellent energy storage performance, ease of fabrication, and stability, thereby enriching the research on polymer-based high-energy density dielectric materials.

Viscoelastic and vibrational studies of nano hybrid fibre metal laminates

Employment of distinct fibres (glass/carbon etc.) in Fibre Metal Laminates (FMLs) is one way of enhancing the durable life of an FML and its performance under dynamic loads. In the present work, carbon fibre is employed in GLARE (Glass/Aluminium laminated epoxy) to enhance the vibration (natural frequency) and viscoelastic (storage modulus ( E′), loss modulus ( E″) and Tan δ) properties. Similarly, the influence of 1 wt% of Al2O3 (alumina), ZrO2 (zirconium oxide) and TiO2 (titanium oxide) nano particles are also studied in hybrid (carbon/glass) FML. The mean particle size of Al2O3 (5.1 nm), ZrO2 (25.3 nm) and TiO2 (63.2 nm) were estimated using the Scherer equation with the aid of X-ray diffractometer analysis. Hybridisation resulted in a 22%, 10% and 2% increase of natural frequencies from mode 1 to mode 3 and 36.3%, 15% and 13.2% of E′, E″ and Tanδ, respectively, when compared to GLARE (glass fibre reinforced aluminium laminated epoxy). TiO2-reinforced hybrid FML shows the highest natural frequencies among all nanohybrid FMLs. The results summarise that natural frequencies and viscoelastic properties of nanohybrid FMLs are sensitive to the type of fibre, nano particle reinforcement and its size. A stereo microscope and a scanning electron microscope (SEM) were used to analyse the defects at the interface and the nanoparticle dispersion in the matrix, respectively. Further, a numerical model was developed to perform free vibration analysis, and it was noticed that the results were similar to experimental values.

Enhancing significantly the strength and tribological response of Al7075 alloy using nano-ZrO2 reinforcement

Ball milling is an effective method for developing a homogenous and refined microstructure for composites. In this study, we synthesized ultrahigh strength Al7075/xZrO2 alloy nanocomposites. These nanocomposites were specially fabricated by the in-situ powder metallurgy technique from high-purity elemental powders through a multi-step process, which included ball milling, uniaxial cold compaction, traditional sintering in an inert atmosphere, and hot extrusion. The ZrO2 nanoparticles with varying volume percentages (x vol.% = 0, 1.25, 2.53, 3.84, and 5.19) were used as a reinforcement. Ball milling was performed to mechanically alloy the elemental powders that reduce the grain size of the powder and homogeneously disperse the nano ZrO2 in the matrix. The physical, mechanical, microstructural, and tribological properties of the nanocomposites were determined. The results showed that adding 2.53 vol.% ZrO2 nanoparticles considerably improved the mechanical and tribological properties. The tensile strength and yield strength of the 2.53 vol.% alloy nanocomposites increased significantly. The wear resistance of the nanocomposite increased up to 5.19 vol.% ZrO2. The results obtained from the newly developed composites were compared with those of Al7075 alloy composites produced earlier.

Surface-interspersed nanoparticles induced cathode-electrolyte interphase enabling stable cycling of high-voltage LiCoO2

The development of high-voltage LiCoO2 (LCO) is crucial for achieving lithium-ion batteries with a high volumetric energy density. However, LCO experiences accelerated degradation at high voltages due to severe interface and structure instability. A uniform and robust cathode-electrolyte interphase (CEI) serves as a vital barrier for protecting the interface. However, the smooth surface of single-crystalline LCO, lacking grain boundaries, poses challenges in generating an effective CEI. Herein, ZrO2 nano-rivets are constructed on the surface of LCO to provide phase boundaries for preferential film-forming sites, inducing the formation of a uniform and robust CEI. The high-quality CEI derived from ZrO2 nano rivets stabilizes the fragile surface of high-voltage LCO and facilitates lithium-ion diffusion. In addition, a Zr diffusion layer is simultaneously built in the LCO bulk. Zr diffusion into the LCO lattice not only effectively suppresses unfavorable phase transitions to stabilize the bulk structure, but also mitigates oxygen charge deficiencies at the highly delithiated state, therefore stabilizing lattice oxygen. Consequently, the modified LCO exhibits excellent capacity retention of 80% after 700 cycles at 4.6 V. This work emphasizes the significance of material surface properties in CEI formation and provides new insights for the design of CEI.

Study of the Structure and Properties of Steel G13 with Modifying and Organic Additives

The purpose of the study – is to determine the effect of modifying and organic additives on the structure and properties of G13 powder steel.Methods. The study of the microstructure and mechanical properties of G13 sludge with modifying and organic additives was carried out. As modifying additives were used: nano-aluminum oxide powder and nano-zirconium oxide powder. The following organic additives were used: ethylene-bis-stearomide, nickel stearate, copper stearate, manganese stearate, iron stearate. The microstructure was studied using an S-3400N electron microscope. Hardness was determined by the depth of the indentation by the Rockwell method. A hardened steel ball with a diameter of 1.56 mm was taken as an indenter. Bending tests were carried out on an MFL HUS-2010z electro-hydraulic tensile testing machine in automatic mode using an IBM PX personal computer.Results. When studying the microstructure of steel G13, it was found that the most fine-grained austenite structure is observed in steel with the following composition of the initial charge: Fe + 14.5% FeMn + 1.2% C + ZrO2 (nano). A uniform structure of austenite with small rounded pores is observed in steel G13, which has the following compositions of the initial charge: Fe + 13% FeMn + 1.3% C + 1% St.Cu; Fe + 14.5%FeMn + 1.2%C + 0.5% St.Mn (warm mix). The study of mechanical characteristics has shown that the best combination of hardness after sintering and bending strength is possessed by workpieces made from a powder mixture of composition Fe + 14.5% FeMn + 1.2% C + 0.5% St. Ni.Conclusion. The most positive effect on the structure of G13 powder steel was exerted by the modifying additive of nano-zirconium oxide powder, as well as organic additives of copper stearate and manganese stearate. The best combination of mechanical characteristics (hardness and bending strength) is exhibited by billets into which an organic additive of nickel stearate was introduced.