ZrC Nanoparticles Research Articles

Zr/Hf-containing metallocene-based ceramic precursors

Polymer-derived-ceramic (PDC) route is an excellent strategy to tailor components at the molecular level, while existing synthetic methods face various problems such as complex preparation, multi-step reaction, and high conversion temperature, etc. Here, we propose an approach to prepare Zr-, Hf-, or Zr/Hf-containing metallocene-based ceramic precursors, which are constructed by the alkylation reaction between cyclopentadienyl ligand and methylene. Through the homogeneous and one-pot reaction occurs, we collect the target products. The reaction condition is mild, and the conversion temperature (1400 °C) is relatively low, and with a high ceramic yield (57.50–66.34%). The obtained metal-containing polymers are further converted to the orthorhombic phase (M7O8.79F9.71, M = Zr, Hf) after pyrolysis at 800 °C. Annealing at an intermediate temperature of 1400 °C in an argon atmosphere results in cubic crystalline ZrC or HfC nanoparticles embedded in a ceramic matrix. The free carbons are in-situ formed after high-temperature treatment, and higher disorder of carbons is observed with increasing temperature. This work provides a good strategy for the potential precursor of ultrahigh-temperature ceramics.

Synthesis and Characterization of ZrC Nano-Powder and its Potential Role to Increase the Cladding Material Properties

Nanocrystalline powders of ZrC were prepared by mechanochemical synthesis of elemental Zirconium (Zr) and Carbon (C) powder. Two different Process Control Agents (PCA’s), i.e. Toluene and n-Hexane were used to avoid the agglomeration of the nanoparticles. For the purpose of the present study, X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDS) have been employed. A complete single phase of fcc-ZrC was obtained after 165 ks of milling time. No impurity other than oxygen was detected in the samples. n-Hexane compare to toluene was observed to inhibit the agglomeration more efficiently. ZrC nanoparticles were successfully synthesized indigenously, using mechanochemical synthesis. This can be used as a potential coating agent in indigenous industry specially the nuclear power industry.

The investigation gamma-irradiated nanocrystalline ZrC particles using infrared, DSC and TG methods

In this study, DSC and infrared spectra of nano ZrC particles were recorded in the 25–[Formula: see text]C temperature and 400–4000[Formula: see text]cm[Formula: see text] spatial frequency range, respectively. All experiments were compared before and after gamma irradiation (5, 15, 50 and 150 Mrad doses). The causes of infrared peaks characterizing C-OH groups and C-O oscillations were investigated in ZrC nanoparticles. Gamma radiation-induced changes are described in the peaks of the IR spectra. The explanation of existing bonds in IR spectra is given by DSC and TG curves. The act of OH groups adsorbed on the surface of nanoparticles and other processes is investigated as a function of temperature with DSC and TG curves.

Low Velocity Impact Behaviour of Composite Laminates Containing TiC and ZrC Nanoparticles in Resin System

Composite structures utilized in defence and aerospace applications might be subjected to impacts due to bird strike, tool dropping and bullet penetration. One of the approaches to this problem is to add nano tubes and nano particles to resin systems in order to improve bonding between fibres and matrix materials. Different nano-particles or nano-tubes of clays, alumina, silica, carbon and graphene have been analysed in composite systems in the literature so far because of the improved mechanical properties. In this study, the low velocity impact behaviour of the aramid fibre reinforced epoxy composite plates, containing two new nano-particles of TiC and ZrC which are not studied formerly, are searched experimentally. After the low velocity impact tests, it is concluded that plates containing titanium carbide nano-particles and zirconium nano-particles yielded 19 % and 4 % respectively less penetration in comparison with particle free plates. In other words, titanium carbide nano-particles contained plates showed more resistance against the impact by 19 % against to particle free plates. These results showed that TiC and ZrC nano particles might be also good contributors for the impact resistance of composite structure.

Grain Size Control by Matrix Phase Additives in Nuclear Thermal Propulsion Cermets

Refined grain sizes in the metallic phase of a cermet nuclear fuel have been reported to provide improved performance and survivability of the fuel in nuclear thermal propulsion (NTP) applications. In this paper, we study the use of ZrC nanoparticles, which have a low neutron absorption cross-section, as Zener pinning sites for the tungsten matrix in a surrogate fuel - yttria stabilized zirconia (YSZ) – cermet. While the ZrC additions were found to successfully pin grain boundaries, subsequent high temperature hydrogen exposure at 2500 K for 1 hour resulted in significantly more catastrophic cracking in comparison to control specimens with no ZrC additions. This increase in cracking is explained by two gas formation mechanisms - hydrogen recombination at defect sites and water vapor formation from the reduction of YSZ.

On the ductilization and the resistance to annealing-induced embrittlement of high-strength W–Re and nano-particle doped W-Re-ZrC alloys

Ductilization and suppression of annealing-induced embrittlement have become the critical premises for various structural applications of high-strength tungsten materials but have yielded few practical advances. Here, we successfully fabricated W–Re and nano-particle doped W-Re-ZrC alloys with a combination of desirable ductility and a high tensile strength above 1.3 GPa by powder metallurgy plus hot swaging. Specifically, the W–Re and W-Re-ZrC alloys exhibit total elongations of 31.6% and 16.1%, respectively, at room temperature. Upon high-temperature annealing at 1600 °C, the W-Re-ZrC alloy still retains a high total elongation of 12.9% and a high tensile strength of over 1.3 GPa, unlike the W–Re alloy, which exhibits substantial losses of ductility and strength. Microstructure analysis reveals that a large amount of low-angle grain boundaries and high-density mobile dislocations are responsible for ductilization. Meanwhile, ZrC nano-particles stabilize low-angle grain boundaries and dislocation structures at elevated temperatures, suppressing annealing-induced embrittlement in the W-Re-ZrC alloy. The present work provides a promising methodology for manufacturing bulk high-strength tungsten materials with favorable room-temperature ductility and high resistance to catastrophic failure during long-term service.

Microstructure and tensile properties of nano-sized ZrC particle strengthened RAFM steels

Reduced activation ferritic/martensitic (RAFM) steels containing ZrC nano particles (ZrC-RAFM steels) were prepared by a combination of spark plasma sintering (SPS) and hot-rolling of the mechanical alloyed powders. Moreover, the microstructure and tensile properties of the prepared ZrC-RAFM steels were investigated. The results show that the ZrC nano particles are uniformly dispersed in the RAFM steels, resulting in a significant decrease in grain size and the enhanced tensile properties of the steels. With the increase of ZrC content, the hardness and tensile strength of the steels are improved, and the mechanism of the improved properties is analyzed and discussed. The tensile strength of the 0.75ZrC- RAFM steel is 2069 MPa, which is 19.6% higher than that (1730 MPa) of the RAFM steel without ZrC. The conclusions provide researchers with the roles of ZrC-nanoparticle in micromorphology and tensile properties of the RAFM steel as potential cladding materials for fast reactors.

FTIR spectroscopy of ZrC nanoparticles under the gamma radiation

In the presented work, infrared spectra of nano-ZrC samples were taken in the range of 400–4000 cm−1 of the wavenumbers before and after gamma irradiation (5 Mrad, 15 Mrad, 50 Mrad and 150 Mrad). As a result of the spectral analysis, it is possible to notice that seven IR bands appear in the general approach before irradiation. The peaks explaining the vibration of the ZrC bonds before and after gamma irradiation were explained by the corresponding wavenumbers in the infrared (IR) absorption spectra. Simultaneously, the stretching vibration of the ZrOC bonds are explained by the effect of gamma radiation and the corresponding wavenumbers. Surface activity of ZrC nanoparticles increased as a result of gamma irradiation and this increasing directly affected to the intensity of infrared peaks, which is characterized the COH groups and CO asymmetric stretching vibration. At the relatively high doses, such as 50 Mrad and 150 Mrad, the state of amorphization in nanomaterials is explained by the corresponding spectra.

Enhanced dielectric properties of polyvinyl alcohol doped with ZrC Nanoparticles

Enhanced dielectric properties of polyvinyl alcohol doped with ZrC Nanoparticles

Enhanced dielectric properties of polyvinyl alcohol doped with ZrC Nanoparticles

In this paper, effect of ZrC nanoparticles on dielectric properties of polyvinyl alcohol has been investigated. The polymer nanocomposites films were fabricated by using casting method. The dielectric properties of prepared nanocomposites were recorded at frequency(f) ranged from100Hz to 5MHz. Results showed that the dielectric properties of polymer were enhanced with increase in the ZrC NPs ratio. The ε' and ε" were reduced while the σAC was rise with rise in the frequency.

Enhanced mechanical properties and thermal stability of hot-rolled Mo-0.5%ZrC alloy

Mo-0.5 wt%ZrC alloy plate with enhanced mechanical properties and thermal stability was manufactured by powder metallurgy and hot rolling. The as-rolled Mo-0.5%ZrC plate shows an ultimate tensile strength (UTS) of 725 MPa and a total elongation (TE) of 24.1% at room temperature. After annealing at 1300 °C, the UTS of Mo-0.5%ZrC alloy decreased to 676 MPa while the TE increased to 32.8%. After 1600 °C annealing, the UTS of Mo-0.5%ZrC alloy is 507 MPa and the TE increased significantly to 56.4%. Additionally, Mo-0.5%ZrC alloy exhibits a high recrystallization start temperature of about 1300 °C. The addition of nanoscale ZrC particles can enhance the strength and high temperature stability by pining dislocations and grain boundaries. Meanwhile, ZrC nanoparticles can also react with the impurity oxygen to form Zr–C–O or ZrO2 particles, and thus alleviate the oxygen embrittlement of Mo alloy. However, the oxide particles tend to grow into larger particles at high temperatures, leading to decreased number density of dispersoids and lower dispersion-strengthening effect.

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.

Microstructure and mechanical properties of in-situ formed ZrC nanoparticles dispersion-strengthened tungsten alloy

W-Zr-C alloy with nanoscale ZrC particles dispersion was fabricated via powder metallurgy method using W, ZrH2 and nanoscale C powders as starting materials. The average size of in-situ formed particles is 55 nm. The smaller particles in the grain interior are dominantly ZrC particles. Zr decomposed from ZrH2 can also react with impurity oxygen to form ZrO2 particles and reduce the detrimental effects of oxygen on grain boundaries. The as-swaged W-Zr-C alloy is ductile at 200 °C, and the ultimate tensile strength and total elongation (TE) at 300 °C are 643.5 MPa and 23.5%, respectively. After annealing at 1400 °C, the UTS at 300 °C of W-Zr-C alloy is still as high as 611.4 MPa and the TE is 33.2%. The recrystallization start temperature of the as-swaged W-Zr-C alloy is between 1400 and 1500 °C, which is 200 °C higher than that of pure W. The in-situ formation of nanoscale second-phase particles via the dissolution-precipitation mechanism provides a feasible strategy for improving the low-temperature toughness and high-temperature stability of tungsten alloys.

Activation of peroxydisulfate via photothermal synergistic strategy for wastewater treatment: Efficiency and mechanism

Peroxydisulfate (PDS)-based advanced oxidation processes (AOPs) have been demonstrated to be an effective technology for the removal of refractory organic contaminants from the aquatic environment. Herein, a photothermal synergistic strategy is developed to realize the green activation of PDS under solar light irradiation. An innovative solar photothermal reaction system and its corresponding evaluation method are established. The results show that there is a synergistic effect between light and light-generated thermal effects on the activation of PDS for effectively removing fulvic acid (FA). The maximum degradation percentage of FA increases from 42.6% to 90.8% after introducing ZrC nanoparticles as photothermal materials. The maximum temperature of the whole system is up to 66.4 ℃ after 120 min irradiation at 0.007 wt% solid content of ZrC, which is higher by 26.9% compared with that in the absence of ZrC nanoparticles. Furthermore, the underlying mechanism and PDS activation efficiency are deeply investigated. This work provides a viable strategy for directly using solar radiation to activate PDS for degrading refractory organic compounds, which creates a new avenue toward the utilization of solar energy for wastewater treatment.

The high thermal stability induced by a synergistic effect of ZrC nanoparticles and Re solution in W matrix in hot rolled tungsten alloy

The synergistic effect of ZrC nanoparticle pining and Re solution in W matrix on the thermal stability of tungsten was studied by investigating the evolution of the microstructure, hardness and tensile properties after annealing in a temperature range of 1000–1700 °C. The results of metallography, electron backscatter diffraction pattern and Vickers micro-hardness indicate that the rolled W-1wt%Re-0.5 wt%ZrC alloy has a higher recrystallization temperature (1600 °C–1700 °C) than that of the rolled pure W (1200 °C), W-0.5 wt%ZrC (1300 °C), W-0.5 wt%HfC (1400–1500 °C) and W–K-3wt%Re alloy fabricated by the same technology. The molecular dynamics simulation results indicated that solution Re atoms in W matrix can slow down the self-diffusion of W atoms and form dragging effect to delay the growth of W grain, moreover, the diffusion coefficient decrease with increasing Re content. In addition, the ZrC nanoparticles can pin the grain boundaries and dislocations effectively, preventing the recrystallization. Therefore, synergistic effect of solid solution Re element and dispersed ZrC nanoparticles significantly increase recrystallization temperature.

Excellent high-temperature strength and ductility of the ZrC nanoparticles dispersed molybdenum

The interface control is critical in the development of high-performance molybdenum (Mo) alloys for high-temperature applications like space reactors. In this work, nanostructured Mo-ZrC alloy with excellent mechanical properties at both room temperature and high temperatures was fabricated by nanoscale ZrC dispersion and interface control. The average grain size of Mo-ZrC alloy is only 0.67 μm owing to the homogeneous dispersion of nanoscale ZrC particles. At room temperature, the ultimate tensile strength (UTS) and total elongation (TE) of the Mo-ZrC alloy are 928 MPa and 34.4%, respectively. At 1000 °C, the UTS is still as high as 562 MPa, which is significantly higher than those reported in oxide dispersion-strengthened Mo alloys, while the TE remains a high value of 23.5%. Additionally, the recrystallization start temperature of Mo-ZrC alloy is about 1400 °C, indicating remarkable thermal stability. First-principles calculations revealed that the interstitial oxygen reduces grain boundary cohesion, while C and ZrC could increase the fracture strength of the boundaries owing to the strong Mo-C bonds. The excellent mechanical properties and thermal stability of the Mo-ZrC alloy can be attributed to a synergistic effect of nanoscale ZrC particles dispersion strengthening, fine-grain strengthening, and grain boundary purification. The strategy could be applied to design other refractory alloys with both high strength and ductility for high-temperature applications.

A Comprehensive Evaluation of ZrC Nanoparticle in Combined Photothermal and Radiation Therapy for Treatment of Triple-Negative Breast Cancer.

Because of the difficulty in treating triple-negative breast cancer (TNBC), the search for treatments has never stopped. Treatment opinions remain limited for triple-negative breast cancer (TNBC). The current treatment approach of using photothermal therapy (PTT) is often imprecise and has limited penetration below the surface of the skin. On the other hand, radiation therapy (RT) has its unavoidable disadvantages, such as side effects or ineffectiveness against hypoxic tumor microenvironment (TME). In this study, we proposed the use of ZrC nanoparticles in conjunction with RT/PTT to enhance antitumor and antimetastatic effect. We modified the ZrC nanoparticle with bovine serum albumin (BSA) and folic acid (FA), sizing desirable about 100nm. The photothermal conversion efficiency was calculated to be 40.51% and sensitizer enhancement ration (SER) was 1.8. With addition of ZrC NPs, more DNA were damaged in γ-H2AX and more ROS were detected with immunofluorescence. In vitro and vivo, the combined therapy with ZrC NPS showed the best effect of tumor cell inhibition and safety. Our results provide evidence that the combination of ZrC NPs, PT, and RT is effective in of TNBC, making it a great potential application for cancer therapy in clinic.

Metal-ceramic carbide integrated solar-driven evaporation device based on ZrC nanoparticles for water evaporation and desalination

Due to the superior characteristics of strong localized surface plasmon resonance, low-cost consumption, and substantial chemical and thermal stability, conductive metal-ceramic nitrides, such as TiN, ZrN and HfN, are considered promising photothermal materials for solar-driven water evaporation and desalination. Transition metal carbides have also been proposed as promising solar absorbers, making them suitable candidates for solar-driven interfacial evaporation and desalination. However, little attention has been paid to this aspect thus far. Here, to gain new insights into the evaporation and desalination performance, we chose ZrC nanoparticles (NPs) as the experimental subject to fabricate an interfacial evaporation device. The highest evaporation rate and evaporation efficiency values were 1.43 ± 0.04 kg m−2 and 98 ± 2%, respectively, for the ZrC NP-integrated device at a loading mass of 85 g/m2. Desalination was further tested using simulated water (3.5% salinity) and collected saline water (21% salinity) as sources, and the evaporation rate and efficiency reached 1.38 ± 0.1 kg m−2 h−1 and 96 ± 0.75%, respectively, under 1 sun illumination. Measurement of ion concentrations following the desalination process demonstrates the effective removal of major saline ions (Na+, Mg2+, K+ and Ca2+).

Preparation and characterization of photothermal polyurethane/zirconium carbide fibrous membranes via electrospinning

Human activities in cold climates are more and more frequent. But, an efficient strategy to maintain the human body temperature is still a challenging work. In this paper, we propose a photothermal polyurethane/zirconium carbide(PU/ZrC) fibrous membrane assembled via electrospinning technique, which can make up for heat lost from the human body by absorbing and converting light energy. When the content of ZrC nanoparticles (Nps) was increased to 8%, the surface temperature of the composite fibrous membrane was increased to 66.5 °C after illumination for 150 s under a Xenon lamp. Besides, the surface morphologies, crystallization behavior, thermal property, mechanical property, wettability and air permeability of the fibrous membranes were also evaluated. The morphology of the fibrous membranes exhibited that mesh-like fibers were densely aligned and the hydrophobicity of the PU/ZrC composites could be improved when ZrC Nps were added. Moreover, the PU/ZrC membrane with low content of ZrC has outstanding mechanical properties and good air permeability. Our results indicate that the PU/ZrC membranes may have promising potentials in the applications of personal thermal management textiles.

Effect of electrodeposition parameters on the evolution of crystallographic texture and internal stress of Ni/ZrC composite coatings

Crystallographic texture and internal stress are two important aspects of microstructures, responsible for various physical and chemical properties of electrodeposited composite coatings. This paper aims to understand how preparation parameters such as current density, size and concentration of second-phase particles, particularly deposition time, influence the crystallographic texture and internal stress of electrodeposited Ni matrix composites. The results show that the evolution of surface morphology, crystallographic texture and the internal stress of electrodeposited Ni/ZrC composites is strongly related to the content of incorporated ZrC in coatings, which increases after an increase in the amount of ZrC particles loaded in the electrolyte, from 0 g/L to 40 g/L, and from a decrease in applied current density, from 20 A/dm2 to 1.25 A/dm2. By increasing the ZrC content in coatings, the crystallographic texture of Ni/ZrC is depressed and internal stress is modified from 329.48 MPa to 56.71 MPa. During electrodeposition, the exhibited texture changes from <111> initial texture to <100> growth texture for pure Ni coatings, and to random orientation for Ni/ZrC coatings. The tensile internal stress of Ni/ZrC decreases, followed by a gradual increasing with an increase of thickness. ZrC nanoparticles incorporation results in Ni/ZrC coatings with a weaker texture and lower internal stress than Ni/ZrC coatings that incorporate ZrC micron particles.