Zirconium Carbide Research Articles

Enhancement of Structural and Optical Properties of CMC/PAA Blend by Addition of Zirconium Carbide Nanoparticles for Optics and Photonics Applications

Nanocomposites of (CMC-PAA-ZrC) made with different nano zirconium carbide percentages by casting method (0, 1.5, 3, 4.5, and 6) wt%. The results showed that FTIR spectra shift in peak position and change in shape and intensity, compared with pure (CMC-PAA) blend. Microscopic photographs show a clear difference in the samples when increasing proportions of zirconium carbide nanoparticles, when the concentration of zirconium carbide NP reached 6% wt, the nanoparticles make up a continuous network inside (CMC-PAA) blend. Structural and optical characteristics have investigated the findings showed that the absorption of (CMC-PAA-ZrC) nanocomposites increases with increasing of ZrC NPs, while transmission decrease. The absorption coefficient, extinction coefficient, refractive index, real and imaginary parts of dielectric and optical conductivity are increasing with rises concentration of ZrC. Also optical energy gap decreased from 4.9 eV to 4.05 eV and from 4.5 eV to 3.65 eV for allowed and forbidden indirect transition respectively with increasing ZrC NPs. The results indicate that the (CMC-PAA-ZrC) nanostructures can be considered as promising materials for optoelectronics applications.

Reactive synthesis of ZrC-ZrSi2 composite coating by atmospheric plasma spraying

In-situ reaction between zirconium and silicon carbide was introduced to atmospheric plasma spraying process to prepare ZrC-ZrSi2 composite coating. The in-situ fabricated ZrC-ZrSi2 composite coating was featured with dense microstructure and promising mechanical properties. Well-arranged whiskers and nanosized spheric grains were observed in the as-prepared composite coating. Water-quenching experiment was conducted to investigate the formation mechanism of the target phase (ZrC and ZrSi2) and the final coating. This work validated the feasibility of preparing ZrC composite coating using Zr-SiC reactive system and furthermore, gave references for preparing ultra-high temperature ceramic coatings by reactive synthesis method.

The pervasive presence of oxygen in ZrC

Based on the recent interest in oxy-carbide materials in catalysis, we employ a thin film model concept to highlight that variation of key reaction parameters in the reactive magnetron sputtering of zirconium carbide films (sputtering power, template temperature or reactive plasma environment) under realistic preparation and application conditions often results in zirconium oxy-carbide films of varying stoichiometry. The composition of the films grown on silicon wafers and in vacuo - cleaved NaCl (001) single crystal facets was confirmed by depth profiling X-ray photoelectron spectroscopy and electron microscopy analysis. A correlation between methane-to-argon ratio, excess carbon and template temperature with elemental composition emphasizes the exclusive presence of oxygen-containing zirconium carbides. To generalize the approach, we also show that embedding of highly ordered Cu particles with uniform sizes in zirconium oxy-carbide matrices yields well-defined metal / oxy-carbide interfaces. As the presence of an oxy-carbide and its reactivity has been inextricably linked to enhanced activity and selectivity in a variety of processes, including hydrogenation, oxidation or reduction reactions, our model thin film approach provides the necessary well-defined catalysts to derive mechanistic details and to study the decomposition/re-carburization cycles of oxy-carbides. We have exemplified the concept for zirconium oxy-carbide, but deliberate extension to similar systems is easily possible.

Zirconium oxycarbides and oxycarbonitrides: A review

AbstractZirconium oxycarbides and zirconium oxycarbonitrides are high‐temperature ceramic materials with great potential for applications in advanced technologies due to their good refractoriness, mechanical and thermoelectric properties, and corrosion resistance. The properties of ZrCO(N) materials strongly depend on their composition. However, the stoichiometry of stable ZrCO(N) compounds, synthesis chemistry, and thermodynamics of the proceeding reactions require clarification. This review comprehensively interprets data for ZrCO and ZrCON ceramics, including studies that may not have been addressed in prior reviews. It summarizes the state‐of‐the‐art synthesis procedures involving reactions between commonly used zirconia, zirconium carbide, and carbon black, along with other zirconium sources widely used in the last few decades for the preparation of ZrCO(N) materials. The controversial reaction mechanisms of carbothermal reduction of zirconia and the role of CO gas in this process are discussed. The properties of ZrCO and ZrCON and their possible applications are also summarized.

Effect of Reinforcement on Tensile Characteristics in AA 5052 with ZrC and Fly Ash-Based Composites

Aluminum Alloy 5052/ZrC/fly ash composites’ tensile properties are changed by the addition of reinforcements and thermal exposure, according to this study. The precipitation hardening of samples manufactured with various weight percent of fly ash and zirconium carbide was employed to improve the properties under thermal circumstances. The tensile properties of reinforced and heat-treated specimens were studied in a series of scientifically-designed experiments. Tensile strength and yield strength rise up to 200°C, after which they begin to decrease slightly (i.e., 250°C) based on the results of the research. Adding reinforcements and exposing the composites to heat increases their elastic modulus which decreases the percentage of El of the composites substantially. Several factors contribute to composites’ increased strength and elastic modulus, the diffusion process, temperatures, and reinforcement composition. It is also possible to manufacture hybridized composite mechanisms for numerous automotive and aviation industries utilizing optimization studies, which interpolate the findings of several sets of parameters to make the process easier.

Optimizing the Parameters of Zirconium Carbide and Rice Husk Ash Reinforced with AA 2618 Composites

Stir casting was utilized to generate the composites. The AA 2618–10wt% zirconium carbide 10wt% rice husk ash hybrid composite had the highest hardness value. In comparison to pure AA 2618, it had a 72% increase. The rule of mixture was used to compute theoretical density, whereas the Archimedes rule was utilized to evaluate real density. For AA 2618, AA 2618/zirconium carbide, and rice husk ash hybrid composites, simple carbide inserts were used for turning. Surface roughness, metal removal rate, and tool wear were among the numerous responses examined. RSM was utilized to analyze and optimize the test outcomes. Feed rate was the most critical issue for surface roughness and material removal rate. Tool wear was shown to be most strongly controlled by tool speed, whereas metal removal rate was found to be least significantly influenced by the weight percent of reinforcement.

Evaluation of the durability of ZrC as support material for Pt electrocatalysts in PEMFCs: Experimental and computational studies

Zirconium carbide (ZrC) is evaluated as support material for corrosion resistance to replace carbon in Pt electrocatalyst for the first time. The commercial ZrC (1 m2g-1) is activated using solid sodium carbonate producing high surface area activated ZrC (a-ZrC, 134 m2g-1). Both ZrC and a-ZrC exhibit good corrosion resistance properties during carbon corrosion tests. As supports in Pt/ZrC and Pt/a-ZrC electrocatalysts, the ECSA losses are below 40% after standard accelerated stress test protocols satisfying the standard set targets of DoE. The Pt/ZrC does not show significant shift in the onset potential in the linear sweep voltammetry after start-up and shut-down protocol tests. The shift in E1/2 potentials for Pt/ZrC and Pt/a-ZrC catalysts, respectively, are 13 mV and 24 mV, which are less compared to 30 mV for Pt/C. The computational analysis shows strong-metal-support-interaction between ZrC and Pt which is responsible for catalyst durability because of higher dissolution potential.

Preparation of zirconium carbide nanofibers by electrospinning of pure zirconium-containing polymer

Zirconium carbide (ZrC) nanofibers were prepared from a pure zirconium-containing polymer by electrospinning without a spinning aid. The product possessed a lower carbon content, which helped in improving its oxidation resistance. The factors affecting the morphology of precursor fibers, such as the concentration of zirconium-containing polymer, spinning voltage, and spinning distance, were further investigated. The zirconium-containing polymer got partially oxidized during the electrospinning process, which led to the requirement of a high conversion temperature from zirconium oxide to ZrC. The pyrolysis of zirconium-containing polymers under vacuum resulted in the formation of ZrC due to the lower activation energy under vacuum compared with that under an argon atmosphere.

First‐Principles Investigation of Phase Stability in Substoichiometric Zirconium Carbide under High Pressure

AbstractNaCl‐type carbides of the early transition metals can exhibit a substantial sub‐stoichiometry at the carbon site, impacting a host of bulk properties that depend upon carbon concentration including melting points, mechanical and elastic properties, and superconducting transition temperatures. Unfortunately, control over vacancies remains challenging with current preparation methods, motivating the search for new synthetic approaches that will allow for the prescription of specific vacancy configurations. Here, density functional theory is augmented with alloy cluster expansion to examine the structure and zero kelvin enthalpy of millions of structures across composition and pressure space. The results are used to examine how extreme pressures might be used to access novel ordered and disordered phases of ZrC, many of which have been calculated to be thermodynamically stable yet remain synthetically elusive. High pressure is shown to significantly reduce sub‐stoichiometry and drive the system toward fully stoichiometric ZrC. They examine the root of these changes and find that pressure exerts an influence over the distribution and abundance of specific nearest‐neighbor vacancy pairs. These results suggest that pressure is a powerful tool for the control of vacancies, and can offer a new synthetic handle on the bulk properties exhibited in this industrially important class of materials.

Investigation of moisture vapor permeability and thermal comfort properties of ceramic embedded fabrics for protective clothing

This study examined the water and moisture vapor permeable and thermal wear comfort of different ceramic imbedded fabrics for workwear protective clothing, and the results are discussed in terms of the thermal radiation and the emissivity characteristics of these fabrics. The water and moisture vapor permeable and thermal wear comfort properties of the ceramic-imbedded fabrics incorporating aluminum oxide (Al2O3)/graphite, zinc oxide (ZnO)/zirconium carbide (ZrC) and ZnO/antimony tin oxide (ATO) were superior to those of the regular polyethylene terephthalate (PET) fabrics due to the greater heat emission of the ceramic-imbedded fabrics. Of three ceramic imbedded fabrics, ZnO/ATO-imbedded fabric exhibited poorer water absorbing and drying properties than those of the Al2O3/graphite and ZnO/ZrC ceramic-imbedded fabrics. The heat retention rate and breathability were also inferior to those of the Al2O3/graphite and ZnO/ZrC ceramic-imbedded fabrics, which were due to the lower far-infrared (FIR) emissivity of the ZnO/ATO-imbedded fabrics. Summarizing the water and moisture vapor permeable and thermal wear comfort properties with heat release characteristics of the different ceramic imbedded PET fabrics, Al2O3 and ZrC ceramic particles imparted a good wear comfort characteristics with superior heat release property, whereas, the ZnO and ATO ceramic particles imbedded fabrics exhibited inferior water and moisture vapor permeable and thermal wear comfort due to the lower heat release of ZnO particles and the heat shielding effect of ATO particles, which is supposed to impart an uncomfortable feeling while wearing workwear protective clothing in cold/dry environments in cold weather regions. These findings suggest that ZnO and ATO particles need to be mixed with ZrC and Al2O3 particles in the yarns to enhance wear comfort of workwear protective clothing.

Pitch resin addition induced evolution of composition, microstructure and mechanical property of C/C-SiC-ZrC composites

Precursor infiltration and pyrolysis (PIP) has been widely used to fabricate C/C-SiC-ZrC composites. However, the use of organic polymeric precursor of zirconium carbide (PZC) can usually cause the degradation of their mechanical property due to the reaction of ZrO2 intermediate with pyrocarbon (PyC) and carbon fibers (Cf) during pyrolysis. In this study, pitch resin was directly added into the mixture solution of PZC and polycarbosilane (PCS) to supply extra carbon. The composition, microstructure and mechanical property of the as-prepared composites were investigated systematically. The pure ZrC-SiC with a high ZrC content is obtained at 1500 °C when the PZC/PCS/resin mass ratio is 20:1:5. The resulting C/C-SiC-ZrC composites have the highest flexural strength of 247.4 MPa since the degradation of PyC and Cf is greatly alleviated by the addition of resin. The damage mechanism of PyC and Cf during pyrolysis was revealed under the different fabrication conditions.

Full Core Criticality Modeling of Gas-Cooled Fast Reactor using the SCALE6.0 and MCNP5 Code Packages

The Gas-Cooled Fast Reactor (GFR) is one of the reactor concepts selected by the Generation IV International Forum (GIF) for the next generation of innovative nuclear energy systems. It was selected among a group of more than 100 prototypes and his commercial availability is expected by 2030. GFR has common goals as the rest GIF advanced reactor types: economy, safety, proliferation resistance, availability and sustainability. Several GFR fuel design concepts such as plates, rod pins and pebbles are currently being investigated in order to meet the high temperature constraints characteristic for a GFR working environment. In the previous study we have compared the fuel depletion results for heterogeneous GFR fuel assembly (FA), obtained with TRITON6 sequence of SCALE6.0 with the results of the MCNPX-CINDER90 and TRIPOLI-4-D codes. Present work is a continuation of neutronic criticality analysis of heterogeneous FA and full core configurations of a GFR concept using 3-D Monte Carlo codes KENO-VI/SCALE6.0 and MCNP5. The FA is based on a hexagonal mesh of fuel rods (uranium and plutonium carbide fuel, silicon carbide clad, helium gas coolant) with axial reflector thickness being varied for the purpose of optimization. Three reflector materials were analyzed: zirconium carbide (ZrC), silicon carbide (SiC) and natural uranium. ZrC has been selected as a reflector material, having the best contribution to the neutron economy and to the reactivity of the core. The core safety parameters were also analysed: a negative temperature coefficient of reactivity was verified for the heavy metal fuel and coolant density loss. Criticality calculations of different FA active heights were performed and the reflector thickness was also adjusted. Finally, GFR full core criticality calculations using different active fuel rod heights and fixed ZrC reflector height were done to find the optimal height of the core. The Shannon entropy of the GFR core fission distribution was proved to be useful technique to monitor both fission source convergence (stationarity) and core eigenvalue convergence (keff) to fundamental eigenmode with MCNP5. All calculations were done with ENDF/B-VII.0 library. The obtained results showed high similarity with reference results.

Leveraging computational thermodynamics to guide SiC-ZrC chemical vapor deposition process development

Using the CALPHAD approach to understand zirconium carbide deposition, a series of phase equilibria were calculated from a custom thermodynamic database based on a literature source, and the equilibria were used to explore the potential chemical vapor deposition (CVD) processing space in the ZrCl4-CH3SiCl3-CH4-H2 system as a function of pressure, temperature, and gas composition. Several gas ratios were considered. At a given ZrCl4:CH3SiCl3 ratio within the range studied, the most important factor was found to be the ratios of CH4:ZrCl4, wherein the nature of the composition – carbide vs. silicide – could be controlled. A pure binary composition of ZrC and SiC is expected to form by increasing the initial amount of methane and decreasing the amount of hydrogen from values predicted purely based on thermodynamic equilibrium. Rietveld analysis of the x-ray diffractograms from corresponding experimental depositions confirmed that increasing the CH4:ZrCl4 ratio increased the fraction of carbon-containing species (SiC, ZrC) and decreased the fraction of non-carbides (ZrSi, ZrSi2, etc.), as predicted from the CALPHAD results.

Strengthening effect of inclusion of ZrC nano-ceramic particles on the corrosion and wear resistance of Ni-P electroless deposits

Zirconium carbide (ZrC) nano-ceramic particles were embedded in the nickel-phosphorus (Ni-P) nanocomposite coating on the surface of N80 steel through electroless deposition strategy. The addition of ZrC can significantly affect the surface morphology, microstructure, wear resistance and corrosion resistance of the coating. Compared with pure Ni-P coating, the average friction coefficient of Ni-P/ZrC (1 g·L−1) composite coating decreased from 0.510 to 0.224, and the specific wear rate is reduced from 1.31 × 10−5 mm3·m−1·N−1 to 2.81 × 10− 6 mm3·m−1·N−1. In terms of improving the corrosion resistance of the coating, Ni-P/ZrC (1 g·L−1) composite coating shows a lower corrosion tendency and a higher electrochemical impedance, and its corrosion rate (4.54 × 10−3 mm·a−1) is one order of magnitude lower than Ni-P coating (5.08 × 10−2 mm·a−1). In addition, the long-term corrosion experiments of the samples show that the composite coating has a longer protective effect on the substrate. Through the analysis of the corrosion morphology, it is found that the improvement of the corrosion resistance of the coating is due to the addition of ZrC, which reduces the surface defects of the coating. At the same time, the labyrinth effect formed between ZrC and the coating can also slow down the corrosion rate.

Influence of pH and temperature parameters on the sol-gel synthesis process of meso porous ZrC nanopowder

In this study, Zirconium carbide nanopowders were synthesized by the sol-gel method in the alcoholic system. Zirconium propoxide and phenolic resin were used as precursors of Zr and carbon, respectively. Sol was prepared in a four-component system of alkoxide, water, catalyst, and dispersant based on the sol-gel chemical process under acidic conditions. After the process of hydrolysis and the formation of gel, the initial powder was heat treated, and ZrC nanoparticles were formed. The impact of pH and temperature parameters on the synthesis process of these nanoparticles was evaluated. SEM/TEM, DTA/TG/XRD/FTIR/DLS analyses were used to assess the properties of the product. The results of sol preparation indicated that Zr-containing precursor particles less than 10 nm could be synthesized by controlling pH around 5. According to the FTIR data, Zr–O and Zr–C bonds were estimated to be 560 and 505 cm−1, respectively. Owing to the zirconium alkoxide hydrolysis and its condensation at 60 °C, Zr–O–C bonds were formed in the presence of the carbon phase. There is a possibility to achieve ZrC products at low temperatures under these conditions, as confirmed by the DTA analysis. DTA/TG analysis indicated that the primary particles of ZrC were generated around 1320 °C, as demonstrated by the X-ray diffraction pattern. BET analysis indicated a high surface area for the particles of approximately 153.42 m2/g, and that the surfaces of these particles were meso porous. SEM microstructure images showed that zirconium carbide particles were formed in a nanometer size range, and particle size distribution was performed within a narrow and uniform range. TEM images and their diffraction pattern reported the synthesis of crystalline carbide particles to be smaller than 50 nm.

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A primary characteristic of zirconium carbide lies in a tolerance on carbon deficiency which is significant for its performance. In this work, ZrCx coatings with controlled stoichiometry (x = 0.49–1.00) were deposited by magnetron sputtering. Based on the results of XRD, Raman, SEM, XPS and TEM, the effects of carbon content on lattice constant and microstructure were revealed. The actual residual stress in ZrCx coatings were detected by XRD-sin2ψ method, which analyzed the lattice parameters in stress-free state and assisted to investigate the lattice constants variation with carbon content. ZrCx coatings remained the NaCl structure with the carbon content varied from 33 at.% to 50 at.%. The ZrCx coatings with low C content exhibited granular grains while the coatings with high C content exhibited a typical columnar grains. Both hardness and modulus firstly increased and then decreased with increasing C/Zr ratio, the maximum value of 24.1 GPa and 432 GPa with ZrC0.86 were identified.

Synthesis and characterization of ZrCx coatings with different stoichiometry

A primary characteristic of zirconium carbide lies in a tolerance on carbon deficiency which is significant for its performance. In this work, ZrCx coatings with controlled stoichiometry (x = 0.49–1.00) were deposited by magnetron sputtering. Based on the results of XRD, Raman, SEM, XPS and TEM, the effects of carbon content on lattice constant and microstructure were revealed. The actual residual stress in ZrCx coatings were detected by XRD-sin2ψ method, which analyzed the lattice parameters in stress-free state and assisted to investigate the lattice constants variation with carbon content. ZrCx coatings remained the NaCl structure with the carbon content varied from 33 at.% to 50 at.%. The ZrCx coatings with low C content exhibited granular grains while the coatings with high C content exhibited a typical columnar grains. Both hardness and modulus firstly increased and then decreased with increasing C/Zr ratio, the maximum value of 24.1 GPa and 432 GPa with ZrC0.86 were identified.

Microstructure of zirconium carbide ceramics synthesized by spark plasma sintering

Zirconium carbide (ZrC) samples were prepared by spark plasma sintering (SPS), at temperatures of 1700 °C, 1900 °C and 2100 °C, all at pressure of 50 megapascal (MPa). The density of ZrC ceramic pellets was measured using a Micromeritics AccuPyc II 1340 Helium Pycnometer. The density of ZrC ceramic pellets was found to increase from (6.51 ± 0.032) g/cm3 to (6.66 ± 0.039) g/cm3 and (6.70 ± 0.017) g/cm3 when the temperature of the SPS was increased from 1700 oC to 1900 oC and 2100 oC respectively. Moreover, the hardness of ZrC ceramic pellets were measured using Rockwell hardness test. The hardness of ZrC ceramic pellets increased from (7.4 ± 0.83) to (17.0 ± 0.073) and (18.4± 0.05) gigapascals (GPa) at temperatures of 1700 oC, 1900 oC and 2100 oC respectively. X-ray diffraction shows the absence of spurious phases or impurity. XRD results showed that, all prepared ZrC samples has the same preferred orientation of the planes (i.e., 200). Furthermore, the average grain size of ZrC was calculated using Sherrers’s equation. The average grain size of the pure ZrC powder increased from 67.46 nm to 72 nm, 79 nm and 83 nm when the ZrC powder was sinteried at temperatures of 1700 oC, 1900 oC and 2100 oC respectively. The differences in the average grain size between the prepared samples leads to show different surface morphologies that monitored by scanning electron microscopy (SEM).

Reactive spark plasma sintering of ZrB2-TiC composites: Role of nano-sized carbon black additive

ZrB2-TiC composites with and without nano-sized carbon black as the sintering additive were densified through spark plasma sintering at 1900 °C for 7 minutes under the applied pressure of 40 MPa. The role of carbon black in densification behavior, phase arrangement, microstructural characteristics and mechanical properties of the sintered composites were then investigated. While both of the composite samples were found to be fully sintered, the thermodynamic of the reactive sintering was also studied. Results indicated that whereas the reactive sintering process leads to complete consumption of TiC through the formation of the solid solution as the matrix in both of the composite samples, the presence of carbon black at the initial composition of the samples can result in remained carbon at the final microstructure. Besides the in-situ synthesized zirconium carbide as the major reinforcement phase, such a remained carbon can lead to significantly different mechanical behavior of the composites. Accordingly, the hardness of 21.8 and 24.3 GPa and the indentation fracture toughness of 3.3 and 4.5 MPa.m0.5 were obtained for carbon-black free and doped samples, respectively. The densification, hardening, and toughening mechanisms in both of the composite samples were finally discussed.

Fabrication and characterization of polyester composite yarn with PVB/ZrC/Al2O3 coating

As a functional textile, photothermal textile materials are receiving more and more attention. A composite yarn was prepared by coating polyvinyl butyral/zirconium carbide/alumina oxide on the surface of polyester yarn through a sizing coating method with the aim to provide a textile substrate with controlled photothermal efficiency. The Box–Behnken design combined with response surface analysis and regression method was used to study the effects of input variables (polyvinyl butyral, zirconium carbide and alumina oxide concentration) on the temperature of the fabric made of polyester/polyvinyl butyral/zirconium carbide/alumina oxide composite yarn under infrared light irradiation. It was found that the effect of polyvinyl butyral and zirconium carbide content on the fabric surface temperature was more significant than that of alumina oxide content. The established regression model could predict the response value (fabric temperature) precisely. The optimal conditions for preparing the polyester/polyvinyl butyral/zirconium carbide/alumina oxide composite yarn were obtained by response surface analysis: 5.9% polyvinyl butyral, 5% zirconium carbide and 0.5% alumina oxide. The structure and properties of the yarn prepared under the optimal conditions were characterized. The results showed zirconium carbide and alumina oxide deposited on surface coating without obvious deterioration of thermal stability and tensile strength. The near-infrared light absorption rate of the composite yarn reached 96.71% and its surface temperature reached 104.0°C after 180 s irradiation under an infrared lamp. The photothermal temperature can still reach 101.5°C after 20 cyclings. The excellent photothermal conversion capacity indicates the polyester/polyvinyl butyral/zirconium carbide/alumina oxide yarn can realize solar energy utilization and be applied in heat management textiles.