ZrC Content Research Articles

Effects of polymer-derived ZiC interlayer on mechanical properties and ablation performance of C/C-ZiC-ZrC-SiC composites prepared by RMI

C/C-ZiC-ZrC-SiC composites were prepared by a combination of PIP (polymer infiltration & pyrolysis) and RMI (reactive melt infiltration) processes on porous C/C composites. The PIP is used for preparing a ZrC-SiC interlayer (denoted as ZiC) between the C/C composites and ZrC-SiC matrix prepared by RMI. Mechanical properties and microstructure of the composites with and without ZiC were characterized. The results show that, the increase of both flexural and tensile strength of the composites after RMI can be optimized by adjusting the ZiC and achieves 50.54% and 56.76%, respectively. The mechanisms can be attributed to the facts that the ZiC effectively protects carbon fibers and PyC from serious erosion by high-temperature melt and weakens the interfacial bond between ceramic matrix and carbon fibers, ensuring a series of stress release under external load. Interestingly, the composites with ZiC also exhibit enhanced ablation performance at ca. 2200 °C due to the improved ZrC content.

Effect of ZrC on the Microstructure and Properties of CrMnFeCoNi High-Entropy Alloy Coatings Prepared by a Plasma Transferred Arc Process.

The low strength caused by the single FCC structure of the CrMnFeCoNi high entropy alloy (HEA) limits its application in the field of coating. Here, we prepared high-entropy alloy coatings of CrMnFeCoNi with different ZrC contents on Q235 steel by a plasma transferred arc process. The effects of ZrC on the microstructure and properties of the CrMnFeCoNi HEA coating were investigated by optical microscopy, scanning electron microscope, and X-ray diffraction and by employing a potensiostat/galvanostat. The results showed that ZrC mainly existed in the coatings as a second phase, having little influence on the main crystal structure and micromorphology of the CrMnFeCoNi HEA coating. The hardness of the CrMnFeCoNi HEA coating increased with the ZrC content. ZrC can effectively improve the corrosion resistance of the CrMnFeCoNi HEA coating. In a 1 mol/L NaCl solution with 4 wt% ZrC, the annual corrosion rate was only 5.997% of that of the HEA coating. Nevertheless, the improvement in the wear resistance of CrMnFeCoNi high-entropy alloy coatings was not apparent with the addition of ZrC. Consequently, the addition of ZrC to the FeCoCrNiMn high-entropy alloy coating holds promise for applications in corrosion resistance, particularly in oceanic environments.

Carbonization of Zr-Loaded Thiourea-Functionalized Styrene-Divinylbenzene Copolymers: An Easy Way to Synthesize Nano-ZrO2@C and Nano-(ZrC, ZrO2)@C Composites

Thermal processing of Zr-loaded ion-exchangers is a facile route to synthetize (ZrO2, ZrC)@C composites. In the present paper, furnace and RF-thermal plasma processing of ZrOCl2 loaded thiourea-functionalized styrene-divinylbenzene copolymer was investigated and led to composites containing ZrO2 and ZrC. Different ZrO2@C composites were formed between 1000 and 1400 °C in 2 h, whereas the composite containing ZrC was created at 1400 °C in 8 h. The ratio of ZrO2/ZrC, the prevailing ZrO2 modifications, and the crystallite sizes strongly depend on the synthesis conditions. The ZrC-containing composites formed only at 1400 °C in 8 h and by the plasma treatment of the ZrO2@C sample prepared in the furnace, resulting in 8 and 16% ZrC content, with 44 and 41 nm ZrC crystallite sizes, respectively. The ZrO2-containing composites (tetragonal, monoclinic, and cubic modifications with 65–88 nm ZrO2 crystallite sizes and 15–43 m2/g BET surface areas) formed in a tube furnace between 1000 and 1400 °C in 2 h. All ZrO2@C composites had both amorphous carbon and graphite, and their ratio is temperature dependent. The carbonaceous compounds were characterized by Raman spectroscopy with analysis of the G and D band intensities. XPS studies showed the surface oxidation of ZrC.

Fabrication of nanocrystalline and ultra-hard tungsten alloy by dual-particle dispersion strengthening

Alloying with heterogeneous atoms or second phase particles is an effective method for inhibiting grain growth and achieving ultrafine and nanocrystalline materials. In this work, by varying the component and content of Ti and ZrC, the synergistic effects of dual-particle reinforcement on sintering behavior and final bulk W alloys were investigated. The results revealed that adding both Ti and ZrC not only dramatically suppresses grain growth but also effectively promotes relative density. Nanocrystalline W-3Ti-1ZrC bulks were successfully fabricated with an ultra-high hardness of 1347 kgf/mm2. Further characterization showed that the alloying component and content strongly influence the milled-powder state agglomeration and morphology even in same milling condition. Additionally, the advantage of Ti and ZrC addition can be utilized simultaneously, as Ti retards grain growth and ZrC reacts with oxygen impurities to enhance grain boundary cohesion.

The microstructural and mechanical behavior of in-situ synthesized ZrB2–ZrC and ZrB2–SiC–ZrC composites: A comparative study

In the present investigation, the ZrB2–ZrC and ZrB2–SiC–ZrC based composites were fabricated via an in-situ reduction mechanism using ZrO2, B4C, Si, and graphite fine powder at 1900 °C in an argon atmosphere. The boro/carbothermal reduction produced nano-sized ZrC grains with ZrB2 particles, whereas the incorporation of Si content produced nano-sized homogeneous distributed SiC grains with ZrB2–ZrC particles. In the ZrB2-based composite densification, microstructure, mechanical, and chemical state identification of elements were investigated. The densification of the samples was enhanced with the formation of ZrC and SiC content, which was correlated with the micrographs and mechanical properties of the samples. The chemical state identification confirms the trace amount of intermediate zirconium oxycarbide in the ZrB2-based composite. Compared to binary ZrB2–ZrC composite, ZrB2–SiC–ZrC composite has finer microstructure and higher densification. The strength of the ZrB2–ZrC and ZrB2–SiC–ZrC composite was decreased by 458 MPa and 406 MPa, respectively. Similarly, the indentation hardness of the samples was increased by 14.2 GPa–15.3 GPa, and fracture toughness was 5.5 ± 0.5 MPa m1/2 to 6.15 ± 0.4 MPa m1/2.

Novel TiC-based ceramic with enhanced mechanical properties by reaction hot-pressing at low temperature

Novel TiC-based ceramics were prepared by reactive hot-pressing at 1400–1600 °C using TiC, Si and ZrC powders as raw reactants for the first time. The effects of ZrC addition and temperature on the microstructure and mechanical properties of ceramics were investigated. The Ti3SiC2 phase existed when the content of ZrC was 10 mol%. The Zr-rich solid solution appeared and the Ti3SiC2 disappeared with 30 mol% ZrC addition. The flexural strength of ceramics was improved due to grain refinement by the pinned SiC, the formation of solid solutions and the Ti3SiC2 phase. The main toughening mechanism can be crack bridging by the layered Ti3SiC2 and crack deflection by the ZrSi particle. TiC-36 mol% Si-10 mol% ZrC (raw composition) exhibits good comprehensive mechanical properties (Vickers hardness of 21.8 GPa, flexural strength of 580 MPa, and indentation fracture toughness of 6.7 MPa m1/2), which reach or exceed most TiC-based ceramics in previous reports.

Ablation and mechanical properties of ZrC-reinforced PBI resin matrix composites

With the rapid development of laser technology, there is an increasing demand for laser protective materials. Thus, the mechanical and ablation properties of composite materials need to be further enhanced. Herein, solution impregnation and hot-press molding were used to develop composites containing various mass ratios of ZrC to polybenzimidazole (PBI) resin (thickness = 3 mm) for laser ablation applications. The results showed that adding short carbon fiber (SCF) to ZrC/PBI composites improves the ablation and mechanical properties. The ZrC/PBI/SCF composites were ablated using a high-energy continuous laser (7 kW cm−2), and the composites did not burn through. The composites did not peel off or split as the ablation process progressed. With the increase in the ZrC content in the composites, dense oxide layers are formed, enhancing the ablation properties of the composites. The ZrC/PBI/SCF composite (the ZrC/PBI mass ratio = 2:1) exhibited the lowest mass loss (2.24%), mass ablation rate (0.119 mg s−1) and linear ablation rate (0.032 mm s−1). This indicates that ZrC/PBI/SCF composites can be used as protective materials in high-energy continuous laser applications.

Oxidation response of ZrB2–SiC–ZrC composites prepared by spark plasma sintering

Considering the importance and application of ultrahigh temperature ceramics in oxidizing environments, in this research, the effect of ZrC content and spark plasma sintering parameters (temperature, time and pressure) on the oxidation response of ZrB2–SiC composites has been investigated. After fabricating the ternary composite samples in different SPS conditions and with different amounts of ZrC, the post-sintering oxidation process was carried out in a box furnace at the temperature of 1400 °C. Increasing the time and temperature of the SPS process caused the decrease in the oxidation resistance of the samples. The reason for such observations was attributed to the extreme growth of grains with increasing the temperature and time of the sintering process despite the better densification of the samples. This research did not reach a clear result about the effect of SPS pressure on composites oxidation behavior. Increasing the amount of ZrC also did not have a positive effect on the oxidation resistance of the samples because this phase itself undergoes oxidation at low temperatures.

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.

Effect of W and C addition on the microstructure and phase composition of W–ZrC composites prepared by using Zr2Cu alloy and variant reactant compositions

W–ZrC composites were successfully fabricated by reacting amounts of Zr2Cu alloy with powder mixtures of varying composition including stoichiometric WC, WC with additional/W (WC/W), and WC with additional/C (WC/C). The use of WC/C powders to reactively form W–ZrC composites with increased ZrC phase content is a new approach that shows potential for ultra-high temperature applications where higher ZrC content, relative to W, is preferred such as land and aeroengines, aerospace thermal protection, and nuclear. The focus of this work was to stabilize diffusion between W and ZrC during formation, limit interfacial phases, and increase the ZrC content. This was done by varying reactant powder compositions while understanding the final phase composition and microstructure. The composites were prepared by heating the powder mixtures to 1400 °C for 8 h in a furnace with 96% Ar - 4% H2 gas atmosphere. The W–ZrC sample prepared using WC/C powders gave the W–ZrC composite with the highest ZrC phase compared to W and showed promise for phase stabilization. Additionally, there was no W2C, or residual WC identified in the final composite indicating complete conversion from WC to ZrC when adding additional carbon to the WC powder. WC/C sample had the highest hardness due to the increased ZrC phase content. This research addresses the critical comparison of carbon addition on the W–ZrC composites and produced composite with high ZrC content, limited interfacial phases and interlocking microstructure.

Fabrication and characterization of ZrC nano-ceramics derived from a single-source precursor and its feasibility as ZrC/C fibers in structure and function

A novel ZrC ceramic precursor was prepared by a polymer-derived ceramics method and ultraviolet (UV) crosslinking by using zirconium tetrachloride (ZrCl4), ethylenediamine (EDA), and diallylamine (DAA) as raw materials. On this basis, polyacrylonitrile (PAN)-based carbon nanofiber (CNF)-coated ZrC ceramic precursors were synthesized by electrostatic spinning. The as-prepared fibers exhibited excellent designability and machinability by adjusting the proportion of precursors. X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM) revealed that these materials are converted to nano-sized ZrC ceramics and ZrC/C fibers with a highly crosslinked network structure after high-temperature annealing. ZrC/C fibers still maintained good electrochemical properties at high temperatures. Finally, the tensile test revealed that the mechanical properties of ZrC/C fibers are significantly superior to those of CNF. Specifically, the ceramic fibers with 25% ZrC content exhibited the maximum tensile strength of 71.7 MPa.

Ablation behaviors of SiC nanowire-reinforced ZrC-SiC coating-matrix integrated C/C composites with different ratios of precursors

A novel method to prepare a coating on the C/C composite is discussed. The precursor infiltration pyrolysis method is usually applied to prepare interior ceramic matrix, thus SiC nanowires that can absorb the surficial precursor are added to prepare surficial ceramics. The method accomplishes the integration of the coating and the matrix so that no coating peels off after ablation. Moreover, the material with a ZrC/SiC precursor ratio of 5:1 (Z5S1), whose mass and linear rates are 0.47 mg/s and 0.95 µm/s, exhibits the highest overall resistance to ablation. The results demonstrate that higher ZrC content and more uniform phase distribution are beneficial to keep ZrO2 in solid and form a denser and firmer oxide layer, which is more effective in improving the ablation resistance of the C/C composite.

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.

Ablation behavior of a network interlacing ZrC-VC ceramic coating prepared by a pioneering spillover permeation

A novel network interlacing ZrC-VC ceramic coating was prepared by a pioneering spillover permeation. With the increase of Zr content in the blind vias, the content of ZrC in the coating and the density of the coating all decrease. The density of the coating on C/C–ZrC–SiC substrate is obviously higher than that on C/C substrate. The linear ablation rate of the novel ceramic coated C/C–ZrC–SiC composites was −0.06 μm/s with about 20 and 1.56 times reduction than C/C composites and C/C–ZrC–SiC composites respectively. The improved ablation resistance was attributed to a dense honeycomb ZrO2 layer filled with liquid vanadium oxide in the ablation center and the improved thermal radiation.

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.

Ablation mechanism of C/C–SiC and C/C–SiC–ZrC composites in hypersonic oxygen-enriched environment

In this study, C/C–SiC and C/C–SiC–ZrC composites were prepared via chemical vapor infiltration and polymer infiltration pyrolysis, and the ablation mechanism under hypersonic oxygen-rich environmental conditions was investigated. The C/C–SiC composites demonstrate an excellent ablation resistance in a hypersonic oxygen-rich environment with a relatively low temperature and speed of approximately 1800 K and 1100 m/s, respectively. It is only in the ablation center area with higher temperatures that a certain degree of thermochemical ablation was observed. The mass and linear ablation rates of C/C–SiC composites (0.027 g/s and 0.117 mm/s, respectively) showed a significant increase in a hypersonic oxygen-rich environment with a temperature and velocity of approximately 2050 K and 2000 m/s, respectively. The high-temperature ablation resistance of ZrC-modified C/C–SiC–ZrC composites improved significantly. However, the ZrC ceramic component had a considerable impact on the ablation resistance of the material. The structural integrity of C/C–20SiC–30ZrC composites was relatively high in hypersonic oxygen-rich environments with a jet temperature and velocity of 2050 K and 2000 m/s, respectively, and mass and linear ablation rates were 0.012 g/s and 0.015 mm/s, respectively. When the ZrC content increased by 40%, the ablation resistance of the composite reduced significantly, whereas the mass and linear ablation rates increased to 0.043 g/s and 0.130 mm/s, respectively.

Development of SiC-ZrC-based ultra-high temperature ceramic coatings via composite method of polymer precursor pyrolysis plus gaseous reactive infiltration

SiC-ZrC-based composite coatings on carbon/carbon composites via ZrC polymer precursor pyrolysis (PPP) plus gaseous reactive infiltration (GRI) of Si or ZrSi 2 , separately denoted as GSIC and GZSIC, were comparatively studied to explore the feasibility and effectiveness of GRI of ZrSi 2 . This composite method by applying ZrSi 2 or Si was proven to similarly produce dense coatings with enhanced coating/substrate interfacial bonding strength for the formed zig-zag transition layer. Furthermore, the GRI of ZrSi 2 instead of Si further increased the UHTC (ZrC) content in the as-deposited coatings resulted from the reaction of infiltrated ZrSi 2 and pre-introduced graphite, enhancing the ablation resistance of the coatings for carbon/carbon composites due to the formed stable Zr-rich Zr-Si-O multiphase oxide. The average mass and linear ablation rates were −0.12 mg/s and 1.56 μm/s for GSIC and −0.3 mg/s and −0.53 μm/s for GZSIC specimens, respectively. The average linear ablation rate of the GZSIC specimen was decreased by ~134% when compared to the GSIC specimen. These results further indicate that the PPP + GRI method with metal silicide MeSi 2 (Me = Zr, Ti, Hf, Cr, etc.) will contribute to the optimal fabrication of dense composite coatings with controllable microstructure, adequate evenly-distributed ultra-high temperature ceramic (UHTC) phases, enhanced interfacial bonding strength and wide circumstance suitability for potential applications. The related work is ongoing in our laboratory. • SiC-ZrC-based coatings were made by precursor pyrolysis plus gaseous reactive infiltration. • Pre-introduced graphite reacted with infiltrated ZrSi 2 further improved ZrC content in the coatings. • The gaseous infiltrated ZrSi 2 instead of Si enhanced ablation resistance of the coatings. • The coating's linear ablation rate was reduced by ~134% as gaseous infiltrated with ZrSi 2 .

Exothermic synthesis of binary solid solutions based on hafnium and zirconium carbides

The paper presents the results of an experimental study into the possibility of producing ultra-high temperature ceramics constituting solid solutions of HfC and ZrC carbides by the single-stage electro-thermal explosion (ETE) method under pressure. Adiabatic flame temperature and phase composition of the equilibrium final product were calculated based on thermodynamic data. It was shown that when the ZrC content in the final product is less than 20 wt.%, adiabatic flame temperature reaches 3800– 3900 K, and the combustion product contains hafnium and zirconium carbides. The effect of mechanical activation modes in an AGO-2 planetary centrifugal mill used for a reaction mixture containing Hf, Zr and C powders on its properties, phase composition formation and the microstructure of carbide solid solutions was studied. It was shown that high-energy mixing in hexane leads to the destruction of the crystal structure of Hf and Zr particles and the formation of amorphous composite particles. The synthesized samples of ultra-high temperature ceramics were studied by X-ray phase and microstructure analyzes. It was shown that exothermic synthesis leads to the formation of single-phase solid solutions of HfC and ZrC carbides with the average particle size of 0.2–1.5 μm. The residual porosity of the binary carbides obtained is 10–12 %. It was found that, despite the high temperature of sample heating during ETE under pressure, the particle size of the resulting solid solutions is significantly (by an order of magnitude) smaller than the particle size of similar complex carbides (20–50 μm) obtained by other methods (SPS and hot pressing). This is associated with the rapidity of the exothermic interaction of the reagents (10–50 ms) during ETE.

Influence of turning parameters on the machinability of Al6061/ZrB2 & ZrC hybrid in-situ Aluminium Matrix Composite

ABSTRACT This paper presents the machining characteristics of AA6061/(0–9 wt%) ZrB2+ ZrC aluminium metal matrix composites using polycrystalline Diamond(PCD). In the present investigation, AMCs were fabricated by in situ reactions between K2ZrF6, KBF4 and SiC particles. The electric stir casting furnace was used to fabricate the AMCs under a controlled environment. X-ray diffraction patterns (XRD) and field emission scanning electron microscope (FESEM) were used to ascertain the formation of ZrB2 and ZrC particles in the AMCs. FESEM micrographs confirmed the uniform distribution of ZrB2 and ZrC particulates along with good interfacial bonding with matrix aluminium alloy. The effect of varying wt% of ZrB2+ ZrC along with cutting speed, feed and depth of cut on machining forces and surface roughness were analysed. FESEM was used to study the morphology of cutting tool, machined surface and chip formation. It was observed that cutting forces reduce with increase in cutting speed due to decrease in built-up edge (BUE) formation and deprivation of dislocation density. The tool wear increased with increase in cutting speed, depth of cut and ZrB2 + ZrC content due to the increase in abrasive action of ceramic particles and reduction of stable BUE.

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.