Zirconium Carbide Research Articles

Characterization of fuel cladding chemical interaction on a high burnup U-10Zr metallic fuel via electron energy loss spectroscopy enhanced by machine learning

Fuel cladding chemical interaction (FCCI) is one of the limiting factors for metallic fuels in nuclear application. A comprehensive analysis of chemical elements in FCCI is the basis for understanding the phenomena and developing potential mitigating strategies. The detection of low atomic number elements (Z < 11) and lanthanide fission products is challenging for energy dispersive x-ray spectroscopy (EDS). This work used scanning transmission electron microscopy (STEM) based electron energy loss spectroscopy (EELS) to study the distribution of carbon and lanthanides in the FCCI region of a solid U-10Zr (wt%) fuel irradiated to 13.2 at. % burnup at fast flux testing facility. Processing the EELS data involved three major steps: 1) enhancing the signal to noise ratio by denoising the spectrum using principal component analysis methods; 2) identification of chemical elements with core energy loss edges; 3) microstructural phase segmentation based on raw EELS spectrums using the K-means clustering method. EELS analysis revealed the formation of zirconium carbide, a rind-like microstructural phase in FCCI region between fuel and cladding. This rind appeared to be intact at this burnup. The study also revealed the shift of plasmon peak between zirconium and zirconium carbide. The EELS mapping also indicated a different distribution of Ce from other lanthanide elements, such as La, Pr, and Nd, suggesting the lanthanides should be separately investigated. The use of the K-means clustering method on the EELS data of FCCI region revealed different phases, especially Fe-Ce and Zr-C, that concurred with the findings from EDS and STEM-EELS elemental mappings.

Comprehensive glass/banana fiber characterization with zirconium carbide filler-reinforced hybrid composites for lightweight structural applications

Comprehensive glass/banana fiber characterization with zirconium carbide filler-reinforced hybrid composites for lightweight structural applications

The Bimodal Epithermal Astronuclear Reactor (BEAR): A Long-Lived, Universal Space Nuclear Powerplant

A neutronic model of a Nuclear Thermal Propulsion reactor based on the NERVA Peewee design using High Assay Low Enriched Uranium (HALEU) fuel in a Zirconium Carbide matrix has been thoroughly characterised and continuously modified over the last few years at the CSNR. The initial design (Emu, for the flightless bird) created in the summer of 2020 and presented at the NETS 2021 conference, has undergone significant adjustments in this time. Two major investigations have been undertaken and evolved over time; one into the requisites for the provision of electrical power to the propelled spacecraft via the circulation of a noble gas mixture in a closed Brayton cycle, and another into the use of planetary regolith as a reflector, reducing neutron leakage at what would otherwise be the reactor’s end of life in vacuo, rekindling it for an extended period of time as well as providing a very easy ultimate disposal solution, replacing the control drums with rods. It was determined that there are no insurmountable obstacles to performance in either mode.

Extrusion-based Additive Manufacturing of Zirconium Carbide for Nuclear Fuel Cell Structures

Extrusion-based Additive Manufacturing of Zirconium Carbide for Nuclear Fuel Cell Structures

Impacts of Zirconium Carbide Incorporated Magnesium Alloy Nanocomposite on Wear Properties

In the study, zirconium carbide nanoparticle (ZrC-50 nm) incorporated magnesium alloy (AZ61) nanocomposite was prepared by liquid state stir cast process, and its wear properties were evaluated by different load (U), sliding speed (V), and sliding distance (W). The impacts on wear rate (WR) and coefficient of friction (COF) of AZ61 alloy nanocomposite were studied. With the support of a pin-on-disc wear tester, the dry sliding wear characteristics were measured. Moreover, to find the optimum process parameter on minimum WR and better COF characteristics, the L27 orthogonal array utilized U, V, and W as the input factors, and the WR &amp; COF were treated as output responses. Based on the analysis, load was found to be the most dominant input factor that influences the WR and sliding distance was the factor for fixing the COF.

Stable Field Emission from Single-Crystalline Zirconium Carbide Nanowires.

The <100> oriented single-crystalline Zirconium Carbide (ZrC) nanowires were controllably synthesized on a graphite substrate by chemical vapor deposition (CVD) with optimized growth parameters involving Zirconium tetrachloride (ZrCl4), flow of methane (CH4), and growth temperature. The length of nanowires is above 10 µm while the diameter is smaller than 100 nm. A single ZrC nanowire was picked up and fixed on a tungsten tip for field emission measurement. After surface pretreatments, a sharpened and cleaned ZrC nanowire emitter showed a high emission current density of 1.1 × 1010 A m-2 at a low turn-on voltage of 440 V. The field emission is stable for 150 min with a fluctuation of 1.77%. This work provides an effective method for synthesizing and stabilizing single-crystalline ZrC nanowire emitters as an electron source for electron-beam applications.

Wear behaviour of titanium diboride and zirconium carbide reinforced LM13 hybrid composite for automotive applications

Abstract This study investigates the wear behaviour of a hybrid composite material reinforced with titanium diboride and zirconium carbide in LM13. The ASTM standard is followed for conducting wear tests, utilizing a pin-on-disc setup to assess the wear rate. An empirical relationship is established to predict the wear rate using statistical tool analysis of variance, and the model’s adequacy is checked. Low wear is observed at a sliding distance of 110 mm, sliding speed of 2.5 m s−1, and sliding load of 12.5 N. The observed low wear is attributed to the optimal level of reinforcement provided by titanium diboride and zirconium carbide. From the analysis of variance, sliding speed is identified as the major contributing factor to wear rate, followed by sliding distance and load. The reinforcement materials enhance the wear resistance of the hybrid composite and their effectiveness is particularly evident under the specified sliding conditions.

A perspective to efficient synthesis of zirconium carbide via novel pyro-vacuum method: lower temperatures and enhanced purity

The use of ultra-high temperature ceramics (UHTCs) as a novel additive in the refractory industry is becoming increasingly popular. However, the synthesis of such materials is associated with some commercial obstacles, mainly high-temperature synthesis methods. In the present study, the pyro-vacuum method is presented as a new method to decrease the final product's synthesis temperature and oxygen content. Some thermodynamic aspects and phase evolution of the materials during the synthesis procedure are described for the synthesis of non-oxide material. Conclusively, it seems that by applying vacuum conditions, the final UHTC phases can be synthesized at significantly lower temperatures (&gt;400 °C lower, for ZrC), if adequate powder mixtures are considered. Also due to phase analysis, it was found that the oxygen content of the final phase is lower than the conventional routes and other references. The process provides promising prospects for the economic synthesis of UHTCs.

Fabrication and properties of photothermal conversion and thermochromic cotton yarn

Purpose This paper aims to demonstrate that, in line with the emerging trend of multifunctional yarn development, cotton yarn can effectively harness renewable solar energy to achieve photothermal conversion and thermochromism. This innovation not only maintains the comfort associated with natural fiber cotton yarn but also enhances its ultraviolet (UV) light resistance. Design/methodology/approach In this work, 4% zirconium carbide (ZrC) and thermochromic powder were adhered to cotton yarn through polyurethane (PU) by sizing coating method. After sizing, the two cotton yarns are twisted by ring spinning to obtain composite yarns with photothermal conversion and thermochromic functions. Findings The yarn obtained by cotton/6%PU/8% thermochromic dye single yarn and cotton/6%PU/4% ZrC single yarn composite is the best match. After 5 min of infrared light, the temperature of the composite yarn rose to the maximum, increasing by 36.1°C. The ΔE* value before and after irradiation of infrared lamp is 26.565, which proves that the thermochromic function is good. The yarn dryness unevenness was significantly reduced by 27.2%. The composite yarn has a UPF value of up to 89.22, and its performance characteristics remain stable after 100 minutes of washing. Originality/value The composite yarn’s photothermal conversion and thermochromism functions are mutually reinforcing. Using sunlight can simultaneously achieve heating and discoloration effects without consuming additional energy. The cotton yarn used in this application is versatile, and suitable for a wide range of uses including clothing, temperature visualization detection and other scenarios.

Synthesis of nanoscale zirconium carbide powders via a two-step process

Herein, ZrC powders with the average particle sizes of 100–300 nm were synthesized via a method composed of vacuum carbothermal reduction followed by calcium treatment. The effects of carbon and calcium addition amounts as well as temperature on the micromorphology of obtained products had been studied, and the involved mechanisms were described. Due to the dissolution-transportation-precipitation mechanism, ZrC grains would grow during the calcium treatment process. The finest ZrC with the average particle size of 126.2 nm could be obtained by the combination of vacuum carbothermal reduction at 1773 K for 4 h and calcium treatment at 1173 K for 4 h, with the carbon addition amount of 1.2 times the theoretical value. Furthermore, carbon defect was found in the final products and the lattice spacing was in good agreement with those calculated by proposed formula.

Development of a highly loaded zirconium carbide paste for material extrusion additive manufacturing

A highly loaded, aqueous-based zirconium carbide (ZrC) paste was developed for ceramic on-demand extrusion (CODE). Commercial ZrC powder was ball milled to reduce the particle size to ∼1 μm. Paste composition was determined by rheological characterization and observation of printing behavior; the final paste consisted of 46–47 vol% ZrC, 43.5 vol% distilled water, 8.1 vol% dispersant, and 1.6 vol% binder. Rheological characterization of the paste showed a yield stress of ∼8 Pa and shear thinning behavior (ΔG′/Δσ* = −55). The paste was printed using a 610 μm nozzle; a test print showed shape fidelity using the developed paste. A pressureless sintering study was performed; a sintering temperature of 2000°C with a 2-hour hold produced samples of 90 % relative density with 3.8 μm grains, which was consistent with literature. The developed paste, in combination with the pressureless densification results, adds a new, ultra-high temperature material to ceramic extrusion additive manufacturing.

Investigation of the growth kinetics of Streptococcus mutans bacteria on Zr-C coating surfaces deposited on 316L stainless steel substrates

The conducted research aims to describe the kinetics of Streptococcus mutans bacteria growth on the surface of Zr-C coatings with varying carbon content deposited on 316L medical-grade stainless steel substrates.The coatings were deposited using the MS PVD (Magnetron Sputtering Physical Vapour Deposition) technique at a constant temperature of 400C. Varying carbon contents in the coatings were achieved by changing the flow rate of acetylene during the process. The dynamics of bacteria growth cultivated at 37C were examined on the surface of the coatings for incubation times ranging from 0 to 72 hours. Generalised logistic functions were utilised for the mathematical description of the obtained results.The produced coatings exhibited varying carbon content, determining the structural composition ranging from a mixture of metallic Zr and ZrC through stoichiometric zirconium carbide to nanocrystalline grains of ZrC in an amorphous carbon matrix. The obtained results unequivocally demonstrate that in the case of ZrC coatings, the carbon content influences both the bacterial growth rate during the proliferation phase and the final population of bacteria.In the conducted research on bacterial population dynamics, only a single strain of Streptococcus mutans was considered, and the mathematical description was limited to reaching a pseudo-steady state by the population.The proposed model can successfully be adapted to describe the dynamics of other individual strains of bacteria dwelling on metallic surfaces as well as coatings.The proposed model can serve as a tool for studying, among other things, inflexion points of logistic curves, which are considered as the boundary between the dominance of anabolic and catabolic processes in the bacterial population.

Computational Insights into the Influence of Surface Functionalization Groups on Zirconium Carbide MXenes as Anode Materials for Lithium-Ion Batteries

Computational Insights into the Influence of Surface Functionalization Groups on Zirconium Carbide MXenes as Anode Materials for Lithium-Ion Batteries

Radio frequency‐assisted zirconium carbide matrix deposition for continuous fiber‐reinforced ultra high temperature ceramic matrix composites

AbstractZirconium carbide (ZrC) is considered to be a potential candidate for ultra high temperature applications due to its high melting point, good chemical inertness, and ablation resistance, but the monolithic form suffers from low fracture toughness and hence poor thermal shock resistance. Reinforcing it using continuous carbon fibers (Cf) to create an ultra high temperature ceramic matrix composite is an obvious solution, however densifying ZrC requires the use of very high temperatures combined with significant pressure, such as obtained by using hot pressing or spark plasma sintering, which risks damaging fibers. In the present work, radio frequency‐assisted chemical vapor infiltration (RF‐CVI) has been investigated with a view to forming Cf/ZrC composites. These initial experiments revealed the ability to deposit pure, nano‐grained, and near stoichiometric ZrC with deposition occurring preferentially from the center of the sample due to the nature of the inverse temperature profile developed. The deposited ZrC grains were in the range of 4–9 nm in size and had a lattice parameter of 0.4750 nm. The work also showed that the use of RF‐CVI enabled the minimization of early pore sealing, a common problem for conventional CVI.

Zirconium carbide modified SiOC composites with porous lamellar structures for broadband microwave absorption and thermal stability

The inherent dielectric properties and thermal stability of transition metal carbides (TMCs) have generated significant interest because of their potential use in electromagnetic (EM) wave applications at various temperatures. However, the high relative complex permittivity and conductivity of TMCs can cause impedance mismatch issues when utilized as absorbers, thereby limiting their effectiveness in absorbing EM waves. To solve these problems, ZrC/ZrO2–SiOC composites with a porous lamellar structure were prepared using polymer-derived ceramics (PDC) technology, which involved dispersing zirconium carbide (ZrC) into modified polysiloxane (PSO). The resulting ZrC/ZrO2–SiOC composite (with 5 wt% ZrC content sintered at 900 °C) achieved remarkable EM wave absorption performance, with a minimum reflection loss (RLmin) of −33.52 dB at 13.0 GHz and an effective absorption bandwidth (EAB) extending up to 7.75 GHz. This exceptional absorption of EM waves is due to the synergistic interplay of various factors such as interface polarization, dipole polarization, and conduction loss. Moreover, the composites exhibit a minimal weight loss of less than 2 % when exposed to air at temperatures ranging from 25 to 1200 °C. This study not only broadens the application possibilities of TMC materials in microwave absorption but also highlights their potential for further improvement and deployment in high-temperature environments.

From properties of zirconium carbide to the reverse design of ultra‐high temperature CMCs

AbstractThe development and commercialization of aerospace vehicles have posed significant challenges to the performance requirements for the corresponding materials. To meet these challenges, ceramic matrix composites (CMCs) have been developed and are widely used in the aerospace industry. However, their stability under extreme environmental conditions still needs to be improved. In this review, some properties of zirconium carbide (ZrC), which are related to extreme environmental applications of CMC are discussed first. Then, the effect of ZrC on the properties of CMC is comprehensively reviewed. ZrC can be introduced into the matrix and coated on the surface to increase the ablation resistance. The protection mechanisms of ZrC addition to CMCs, and the improvement in ZrC ablation resistance are explained. In addition, some perspectives on future developments are given.

Numerical Study of Porous Cylindrical Containment for the Fuel Element of a Centrifugal Nuclear Thermal Rocket

For deep-space propulsion and interplanetary exploration, the centrifugal nuclear thermal rocket (CNTR) has the ability to achieve a very high specific impulse (Isp) metric beyond that of conventional chemical rockets or solid-core nuclear thermal propulsion systems. The high Isp allows the rocket to use less propellant or achieve a higher velocity for shorter transit times. However, the cylindrical containment structure of a CNTR fuel element encounters extreme conditions, as it houses molten uranium at temperatures exceeding 1408 K, leading to challenges such as dissolution, chemical reactions, and thermal stresses that conventional materials struggle to withstand. This study aims to address this issue by analyzing appropriate materials for constructing the cylindrical containment component. The operating conditions of the annular porous medium that confines the liquid uranium in the centrifugal fuel element are simulated by conducting a comprehensive one-dimensional numerical analysis using a range of candidate porous materials, including Mo, W, zirconium carbide, and silicon carbide. The porous structure facilitates the flow of the hydrogen propellant into the internal molten uranium section, where it gains significant thermal energy while simultaneously cooling the cylinder. The containment cylinder has an internal temperature of 1478.1 K, exceeding the melting point of uranium, while the external gas temperature of the hydrogen propellant is much lower. This temperature difference induces significant thermal stresses in the cylinder. The porous containment cylinder made from molybdenum was able to maintain elastic deformation throughout the thickness of the cylinder, showcasing its ability to handle these extreme thermal stress conditions. Tungsten, on the other hand, experienced plastic deformation at the cylinder’s edges and elastic deformation through the middle radial locations. In contrast, the stresses experienced by the ceramic materials far exceeded their failure stress values, leading to brittle failure. These findings will help with the refinement of the CNTR design, edging it closer to practical implementation.

Thickness-dependent structure and properties in zirconium carbide ceramic via orientated deposition

The fine-tuning of controlled structure and property evolution of zirconium carbide (ZrC) ceramic is essential for its functional applications, especially with insufficient understanding of the size effect mechanisms. In this investigation, the physically vapor-deposited ZrC (PVD-ZrC) ceramic was fabricated through magnetron sputtering, with a specific focus on its thickness-dependent growth and evolution of composition, microstructure, growth texture and mechanical properties. As prepared PVD-ZrC presents a hybrid structure characterized by amorphous carbon and nanocrystalline ZrC, with diversity in crystallinity, crystallite size, and growth pattern determined by target power, gas-flow pressure and substrate temperature. Moreover, the PVD-ZrC ceramic deposited by directional deposition, exhibits a structure transition from equiaxed crystals to dense columnar fiber crystals and an isotropy-toward texture. As the thickness increases, the stress gradually shifts towards tensile stress with a weaker fracture toughness. Through the First-principle calculation, it is illustrated that the mechanical properties of bulk polycrystalline ZrC are evidently different from low-dimensional polycrystalline ZrC film. This mechanism of thickness-dependent structure and properties is dominant by the surface effect, size effect, grain boundary effect, and stress effects.

Effect of zirconium carbide coating on thermal behavior of heavy duty V12 diesel engine using finite element method

Thermal losses and emissions are considered as major contributing factors in decreasing the efficiency of engines and life span of engines. To prevent heat losses and emissions, thermal ceramic coatings are considered as potential contenders. Moreover, ceramic coatings also prevent engine parts from damage due to thermal stresses. In this computational study, the effect of Zirconium Carbide coating on the thermal behavior of V12 engine is explored. Geometry of V12 engine’s piston and cylinder is generated in SolidWorks 2016. After that, piston’s surface and cylinder’s inner walls are coated with Zirconium Carbide ceramic coating and thermal behavior is analyzed using ANSYS Workbench 19.2. Two cases are discussed in this work. In the first case, piston is made of Al-3003 alloy and cylinder walls are made of gray cast iron whereas in the second case, whole assembly is made of Al-3003 alloy. Temperature and heat flux profiles of both the cases are compared with coating and without coating. Maximum temperature is recorded to be at the top of piston head surface. The results show 44.9% increase in maximum temperature for the first case whereas 83.5% increase in the second case. Heat flux results after show reduction after coating. Zirconium Carbide ceramic coatings can act as thermal barrier and prevent engine parts from thermal stresses. Moreover, it provides insulation to cylinder which prevents heat transfer and retains more temperature inside the cylinder which in turn enhances the efficiency.

Evaluation of nanocrystalline ZrC under gamma irradiation and high pressure

Zirconium carbide (ZrC) is known for its exceptional properties, positioning it as a leading ultrahigh-temperature ceramic for diverse applications such as coating, oxygen-gettering, and inert matrix utilization in advanced high-temperature reactor fuels. Its impressive resistance to fission product corrosion, superior fission product retention capabilities, and resilience against hydrogen corrosion further highlight its significance in these fuel systems. In this work, the structural properties of zirconium carbide crystals (particle size of 20 nm) irradiated with 60Co gamma source were investigated at absorption doses from 300 kGy up to 3000 kGy using X-ray diffraction (XRD). Furthermore, the crystallinity properties of the crystals under high-pressure conditions were examined using the Small-angle X-ray Scattering (SAXS)/Wide-angle X ray scattering (WAXS) Xeuss 3.0 system. A comparative analysis of theoretical calculations and experimental results was conducted. The crystalline size experienced a decrease, while the microhardness showed variation. ZrC was identified to possess an Face Centered Cubic (FCC) – B1 structure of transition metal carbides (TMCs), with specific atomic arrangements. Under high pressure conditions, ZrC exhibits a shift to higher two-theta angles with compression of all diffraction peaks, without the formation of new peaks, up to a pressure of 9.0 GPa.