A review of the properties of hybrid ceramic nanocomposites

We fabricated ceramic ZnS nanocomposites by mixing fly ash of a thermal power plant and waste glass powder with ZnS nanoparticles manufactured by a template-free hydrothermal treatment method. Ceramic ZnS nanocomposites with structure and mechanical properties produced using powder mixtures were obtained by applying milling and annealing procedures at a heat treatment temperature of 700 °C. Its photocatalytic activity was evaluated with methyl orange (MO), acetaldehyde (ATA), 2,4-dichlorophenoxyacetic acid (2,4-D), and methylene blue (MB) as photodegradation targets. Crystallization behavior of ceramic ZnS nanocomposites prepared in this study was examined through X-ray diffraction (XRD) analysis and surface morphological observation. Chemical composition of the ceramic ZnS nanocomposites was estimated using field emission-scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectrometry (EDS). Its physicochemical properties were characterized by measuring density, compressive strength, bending strength, and chemical durability according to ZnS nanoparticle content. Results confirmed that addition of ZnS nanoparticles significantly improved physicochemical properties of the prepared nanocomposite samples. As the content of ZnS nanoparticles increased, photocatalytic activity of ceramic ZnS nanocomposites with and without acid treatment for photodegradation target material also increased under UV light irradiation. Degrees of photocatalytic degradation of MO, ATA, 2,4-D, and MB by ceramic ZnS nanocomposites added with 20 wt% ZnS nanoparticles (after immersion in acidic solution) were about 0.285, 0.118, 0.280, 0.256 after UV irradiation for 180 min, respectively. Moreover, the photocatalytic degradation rate of target substances for photodegradation was estimated using pseudo-first-order kinetics proposed by Lagergren.

As nanoscale reinforcements, the graphene and graphene oxide nanoplates exhibit distinct mechanical and physical properties. The determination of the effective elasto-plastic behavior of nanoplate/ceramic nanocomposites and the different filling effects of graphene and graphene oxide nanoplate deserve systematic investigation. In this work, we intend to uncover how the graphene and graphene oxide nanoplates affect the macroscopic elasto-plastic characteristics of ceramic matrix nanocomposites and what differences in both nanoplates enhancements. A homogenization model is first utilized for determining the effective elastic parameters of nanoplate/ceramic composite with a perfect interface. Then the slightly weakened interface model is introduced to characterize the sliding effects of nanoplates in a ceramic matrix, and the effective elastic parameters of such nanoplates filled composites incorporating the interfacial sliding effects are explicitly formulated. Furthermore, a nonlinear micromechanics model is developed to investigate the macroscopic elastoplasticity and the yield behavior of graphene and graphene oxide nanoplate-filled ceramic nanocomposites subjected to confining pressure. The filling effects of the two kinds of nanoplates on the mechanical properties of such nanocomposite are comparatively examined. The calculated results demonstrate that types of the nanoplates and the imperfect interfaces between nanoplates and ceramic matrix have significant influences on the effective elasto-plastic behaviors of the nanoplate composites.

This research investigated a Bismuth-based ceramic nanocomposite material with the stoichiometric composition Bi?.?Pb?.?Sr?Ca?Cu?O_y (abbreviated as B(P)SCCO-2223), synthesized via the solid-state reaction method. The fabrication process involved compound composition calculations and powder metallurgy using several high-purity oxide precursors, with bismuth oxide as the primary component. Heat treatment in the form of sintering was conducted at 846?°C for durations of 32 and 34 hours to examine its effects on the material’s physical properties. Scanning Electron Microscopy (SEM) analysis revealed layered grain structures with the presence of pores at grain boundaries. Energy Dispersive X-ray (EDX) analysis confirmed that the target 2:2:2:3 elemental ratio was achieved across all samples. X-ray Diffraction (XRD) analysis showed that the sample sintered for 34 hours exhibited the largest grain size of 48.07?nm. The holding time of 34 hours during the sintering process has provided sufficient opportunity for the crystal grains to grow larger. Scanning electron microscopy photos also show that longer sintering times make the empty space between the grains smaller because the crystal grains are closer together, followed by the pore size becoming smaller. This sample also demonstrated the highest oriented phase percentage (58.12%) and the lowest impurity level (6.05%). Mechanical properties, evaluated using Vickers microhardness testing, indicated that the 34-hour sintered sample had superior performance, with a Vickers hardness of 0.905?GPa, Young’s modulus of 74.2?GPa, yield strength of 0.301?GPa, fracture toughness of 5.17, surface energy of 0.18?J, and a brittleness index of 0.175. Overall, the study concluded that the physical properties of the ceramic nanocomposite improved with increased sintering duration.

The present Review addresses current developments related to polymer-derived ceramic nanocomposites (PDC-NCs). Different classes of preceramic polymers are briefly introduced and their conversion into ceramic materials with adjustable phase compositions and microstructures is presented. Emphasis is set on discussing the intimate relationship between the chemistry and structural architecture of the precursor and the structural features and properties of the resulting ceramic nanocomposites. Various structural and functional properties of silicon-containing ceramic nanocomposites as well as different preparative strategies to achieve nano-scaled PDC-NC-based ordered structures are highlighted, based on selected ceramic nanocomposite systems. Furthermore, prospective applications of the PDC-NCs such as high-temperature stable materials for thermal protection systems, membranes for hot gas separation purposes, materials for heterogeneous catalysis, nano-confinement materials for hydrogen storage applications as well as anode materials for secondary ion batteries are introduced and discussed in detail.

Synergic influence of MWCNTs and SiC nanoparticles on the microstructure and properties of Al2O3 ceramic hybrid nanocomposites

Metal and ceramic matrix composites have been developed to enhance the stiffness and strength of metals and alloys, and improve the toughness of monolithic ceramics, respectively. It is possible to further improve their properties by using nanoreinforcement, which led to the development of metal and ceramic matrix nanocomposites, in which case, the dimension of the reinforcement is on the order of nanometer, typically less than 100 nm. However, in many cases, the properties measured experimentally remain far from those estimated theoretically. This is mainly due to the fact that the properties of nanocomposites depend not only on the properties of the individual constituents, i.e., the matrix and reinforcement as well as the interface between them, but also on the extent of nanoreinforcement dispersion. Therefore, obtaining a uniform dispersion of the nanoreinforcement in the matrix remains a key issue in the development of nanocomposites with the desired properties. The issue of nanoreinforcement dispersion was not fully addressed in review papers dedicated to processing, characterization, and properties of inorganic nanocomposites. In addition, characterization of nanoparticles dispersion, reported in literature, remains largely qualitative. The objective of this review is to provide a comprehensive description of characterization techniques used to evaluate the extent of nanoreinforcement dispersion in inorganic nanocomposites and critically review published work. Moreover, methodologies and techniques used to characterize reinforcement dispersion in conventional composites, which may be used for quantitative characterization of nanoreinforcement dispersion in nanocomposites, is also presented.

Glide of hollow fibers at the bridging stage of fracture in ceramic nanocomposites

Development of multicolor 3D-printed 3Y-ZrO2 sintered bodies by optimizing rheological properties of UV-curable high-content ceramic nanocomposites

Inclusions of nanosized ceramic particles in a polymer matrix influence the dielectric properties of their composite more when compared to conventional microcomposites through a greater interfacial contact area between the filler particles and the polymer per volume. This review summarizes the research of and potential for polymer−ceramic nanocomposite use as electrostatic energy storage materials. A particular focus is made on the role of the interfacial region, properties and characterizations, and the significance of controlling the nanofiller surface for improving the energy storage capacity by nanocomposite dielectric capacitor films. Various types of surface modifications and methodologies that have been applied to ceramic nanofillers in an effort to control dielectric properties of the polymer nanocomposites are reviewed. Special mention is made of new structure-property-relationships at the interface through altering the chemical and electronic nature of the particle-polymer interface. Recent research results suggest that ligands, as a function of their electron density influence at the filler surface, reduce filler surface conductivity to maximize the dielectric energy storage density while reducing dielectric losses. The article concludes by briefly revisiting theoretical models of the filler-polymer interface structure property as an influence on properties of polymer−ceramic nanocomposite dielectrics.

4 - Failure mechanisms of ceramic nanocomposites

Hybrid multilayer graphene and SiC whisker reinforced TiB2 based nano-composites by two-step sintering

In this research, using pyrolysis of phenolic resin in the presence of silicon particles, the SiC ceramic composite is formed. The samples were prepared by introducing 30, 35, 40, 45 and 50 wt% of Si particles to the phenolic resin. The samples were cured at 180°C then carbonized at 1100°C. The final carbonized C/Si composites are hot-pressed at 1500°C in inert atmosphere, which is more than the melting point of Si particles. In this temperature, Carbon vapor and melted Si react and SiC ceramic is formed. The XRD analysis of samples showed that SiC peak was observed in the final product while carbonized phenolic and Si particles also existed in the matrix. The samples were so brittle and therefore, several impregnation processes should have been used to reduce the porosity of composite. SEM images of in situ composite reveal extraordinary phenomenon which is related to the formation of CNT and nanostructures on the base of Si particles that grow like flower in the matrix. These nanostructures are one of the reasons for higher mechanical properties of final nanocomposite. Three-point flexural tests are also conducted for better understanding of mechanical improvement.

Micromechanical properties of hydroxyapatite nanocomposites reinforced with CNTs and ZrO2

In this work, we characterized the mechanical and electrical properties of zirconia-based ceramic nanocomposites reinforced with 30 and 40 vol. % TiN and fabricated by spark plasma sintering. In addition to their improved mechanical performance, these compositions have sufficient electrical conductivity to allow wire electrical discharge machining (WEDM). The influence of WEDM variables on the roughness and the mechanical strength of samples was analyzed after each cut. The experimental results showed that the roughness of machined surfaces can be reduced by variations in WEDM manufacturing regimes, and, consequently, a drastic drop in flexural strength of workpieces can be avoided. Furthermore, the composites with higher content and homogeneous distribution of the conductive phase exhibited better surface quality as well.

The potential of a ceramic nanocomposite technique employing a simple bimodal particle size packing and a pressureless sintering process as a low-cost and simple ceramic processing to obtain perovskite ferroelectric ceramics in the PMN/PT system was demonstrated. Attention was focused on relationships between chemical composition, densification, microstructure, and electrical properties. It has been found that the phase formation, microstructures, and dielectric properties of ceramic nanocomposites are totally different from those of typical solid solutions.