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Journal of the Australian Ceramic Society
Number of Followers: 0  Hybrid journal (It can contain Open Access articles)ISSN (Print) 2510-1560 - ISSN (Online) 2510-1579 Published by Springer-Verlag  [2468 journals]
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- Structural and electrical charge transport properties in oxygen-deficient
PbTiO3−δ ceramics-
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Abstract: Oxygen-deficient perovskites (PbTi1−xFexLiyO3−δ, x = 0–0.25, y = 0.15) were prepared by gel combustion technique. This study presents the effect of Fe3+ and Li+ on the morpho-structural and electrical properties of ceramics. Two structural behaviors have been identified, depending on the Fe3+ amount. At low Fe3+ concentrations (3.7%), the variation of the cell parameters is given by the tetragonal change toward cubic phase while at higher levels (>15%) the variation of the cell parameters comes mainly from Fe3+/Ti4+ ionic radii differences. Fe3+ doping at Ti sites creates oxygen and titan vacancies in order to compensate the Ti4+ charge. Introduction of oxygen vacancies reduces progressively band gap energy from 3.28 to 2.63 eV. ICP-OES measurements show that Pb and Ti are lower than theoretical formula which it generates supplementary contributions to the oxygen deficiency. Addition of Fe3+ and Li+ leads to an increase of lattice micro-strains from 17.07·10−4 up to 24.44·10−4, improving ionic conduction. Moreover, DFT calculation shows that the lattice distortion tends to decrease with the increase of the Fe concentration, in agreement with the XRD. Based on BET analysis, the pore diameter decreases from 56.9 to 16.6 nm with the increase of iron amount and is correlated with the relative densities that increase from 82.0 to 91.27%. According to EIS investigations, activation energy varies between 0.632 and 0.950 eV, showing that the conduction in perovskite ceramics is based on double ionized oxygen vacancies. The highest conductivity at 500 °C was obtained for samples doped with 15% Fe and 25% Fe (2.4 × 10−3 S·cm−1), sintered at 750 °C. Graphical abstract
PubDate: 2023-05-29
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- Structural and physical properties of Ce1-xKxMoO3 for x = 0.0, 0.2,
and 0.4 prepared by sol–gel method-
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Abstract: The perovskite Ce1-xKxMoO3, where x = 0.0, 0.2, and 0.4, was prepared using sol–gel technique. Samples were characterized by X-ray diffraction (XRD), differential scanning calorimetry DSC, X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, impedance spectroscopy UV–VIS, diffuse reflectance spectroscopic, and photoluminescence (PL). Besides, the XRD and Raman spectroscopy revealed an orthorhombic phase with a Pnma space group for Ce1-xKxMoO3 samples. XPS analysis proved the existence of Mo3+ and Mo4+ ions. On the other hand, Raman spectroscopy has particularly shown the existence of the B1g mode associated to the MoO6 octahedron. And the DSC curves mark the absence of inflections which qualitatively shows the thermal stability of Ce1-xKxMoO3. Moreover, impedance spectroscopy confirmed that DC conductivity can be justified by the Arrhenius law at 475–600 K temperature range; the activation energy (≈0.314 eV) decreased with the potassium amount and by Mott’s VRH model for T < 445 K. In addition, the density’s greatest value of Fermi states, N(EF) values 1.07 1023 eV−1 cm−3, and a low relaxation time τrel≈0.5 μs were obtained with CKMO04 sample. In the end, the Tauc curves revealed that the bandgap decreased from 3.10 to 2.77 eV with K+ amount; the PL measurements exhibited intense emission of visible and near-infrared light under UV light excitation. In conclusion, all results found allow Ce1-xKxMoO3 to be too useful in the field of optoelectronics.
PubDate: 2023-05-24
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- Influence of dispersant on the microstructure and performance of the
hot-pressed B4C-YB4 ceramics-
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Abstract: The influence of different dispersants on the dispersion of Y2O3 sintering aid in B4C powder and the microstructure and performance of the subsequently hot-pressed ceramics were studied in this paper. The results indicated that ammonium polycarboxylate (APC) could effectively enhance the distribution of Y2O3 in B4C powder, and further improve the distribution homogeneity of the formed second phase YB4 in the fabricated ceramics. Polyethyleneglycol (PEG) 600 was beneficial to breaking the Y2O3 agglomeration in B4C powder and improving the distribution of YB4. The remaining PEG 600 in the mixed powder would react with B4C and Y2O3 particles to form the dendritic-structure second phase in the sintering process, which comprised some whisker-like branches and a layer of film. The distribution of YB4 in the fabricated ceramics was slightly improved by adding sodium citrate (SC) dispersant. Y2O3 reacted with B4C to form the intergranular and intragranular YB4, and liquid phase was formed in the sintering process, facilitating the rearrangement of B4C grains and improving the densification. The dispersant APC could improve the homogeneity of YB4, promoting the densification and strength of the ceramics.
PubDate: 2023-05-22
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- Single step calciothermic synthesis of nickel boride particles in molten
salt-
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Abstract: In this study, production of nickel boride (NixB) via calciothermic reduction in molten salt has been studied. Firstly, the electrochemical behaviors of CaO and NiO in CaCl2 melt were examined by cyclic voltammetry (CV). Then, the influences of the process parameters (temperature (1173–1273 K) and time (15–60 min)) on the powders were investigated. Based on the CV results, it was understood that NiO reduction takes place in one step at -0.25 V. Temperature investigations revealed that Ni and Ni2B phases that were present at low temperatures disappeared as the temperature increased. The Ni3B and Ni2B ratios in the particles increased as the duration went on, and almost no Ni left in the particles after 60 min. The magnetic properties of the particles were investigated and, the saturation magnetization, coercive and remanent values were determined as 25.063 emu/g, 32.694 Oe, and 0.903 emu/g, respectively.
PubDate: 2023-05-18
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- The effect of calcination on alkali-activated lightweight geopolymers
produced with volcanic tuffs-
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Abstract: Evaluating the use of waste products and creating environmentally friendly composites are among the leading issues today. Geopolymers have an important role in making use of waste materials. In order to investigate the usability of volcanic tuff wastes in the production of geopolymer composites, two different tuffs and calcined types of these tuffs were used. Many researchers have studied geopolymers containing metakaolin, but geopolymers containing volcanic tuffs are very limited. This study will contribute to the limited issue in the literature and more effective use of waste volcanic tuffs that cause environmental pollution will be contributed. This study produced a lightweight geopolymer using two different natural pozzolans. The calcination effect was investigated by calcining the two pozzolans used at 800 °C for 3 h. 48 lightweight geopolymer composites were produced using normal and calcined volcanic tuffs by using two different amounts of activator (NaOH + Na2SiO3), two different activator ratios (NaOH/Na2SiO3) and three different expanded polystyrene (EPS) ratios. Density, water absorption, compressive strength, compressive strength changes after elevated temperature, XRD and FT-IR test results were examined. While the highest strength was determined as 34 MPa in Tuff-1 mixtures in normal tuff samples, it was measured as approximately 57 MPa in Tuff-2 mixtures after calcination. The densities of the samples produced by calcined tuff were higher, and the water absorption ratios were lower. As a result of calcination, there were differences in the morphological structure and bonds formed based on the XRD and FT-IR graphics.
PubDate: 2023-05-17
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- Dielectric and scattering properties of transparent SiC composite in
X-band range for radome application-
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Abstract: Transparent SiC composites to microwave were fabricated using cold pressing method followed by sintering process at 1200 °C in air environment. However, zinc oxide and silicon were utilized as fillers. The X-ray diffraction and surface morphology revealed a crystal microstructure changes throughout the different mixing ratios of the composites associated with some pores due to sintering process, whereas SiO2 was detected in all XRD patterns duo to the oxidation of the Si. The dielectric properties and scattering characteristics of all composites in x-band were elucidated. The results showed low dielectric properties ~ < 5 in composites 70/20/10, 80/5/15, 80/10/10, 90/7.5/2.5, and 90/15/5 due to the increased oxidation in the composite that assist of charge mobility to passing through the thickness. On the other hand, all composites exhibited reflection loss higher than − 10 dB. This reduction accompanying increase of the transmission coefficient to be nearly 60% in which place the composite to be a promising candidate to microwave range.
PubDate: 2023-05-17
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- Physico-chemical characterization and in vitro biological study of
manganese doped β-tricalcium phosphate-based ceramics for bone
regeneration applications-
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Abstract: This work evaluates the effects of manganese (Mn) doping on the morpho-structural features, mechanical performance, and in vitro biological response of beta-tricalcium phosphate (β-TCP) derived bioceramics for bone tissue engineering applications. Five different Mn doping levels (i.e., 0.01%, 0.05%, 0.1%, 0.5%, and 1 wt.%) were investigated, with the β-TCP-based bioceramics being sintered at four temperatures (i.e., 1000, 1100, 1200, and 1300 °C). A densification improvement was induced when using Mn in excess of 0.05 wt.%; the densification remained stationary in the sintering temperature range of 1200 − 1300 °C. The structural analyses evidenced that all samples sintered at 1000 and 1100 °C were composed of β-TCP as major phase and hydroxyapatite (HA) as a minor constituent (~ 4–6 wt.%). At the higher temperatures (1200 and 1300 °C), the formation of α-TCP was signalled at the expense of both β-TCP and HA. The Mn doping was evidenced by lattice parameters changes. The evolution of the phase weights is linked to a complex inter-play between the capacity of the compounds to incorporate Mn and the thermal decomposition kinetics. The Mn doping induced a reduction in the mechanical performance (in terms of compressive strength, Vickers hardness and elastic modulus) of the β-TCP-based ceramics. The metabolic activity and viability of osteoblastic cells (MC3T3-E1) for the ceramics were studied in both powder and compacted pellet form. Ceramics with Mn doping levels lower than 0.1 wt.% yielded a more favorable microenvironment for the osteoblast cells with respect to the undoped β-TCP. No cytotoxic effects were recorded up to 21 days. The Mn-doped β-TCPs showed a significant increase (p < 0.01) in alkaline phosphatase activity with respect to pure β-TCP.
PubDate: 2023-05-12
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- Synthesis and characterization of high surface area mesoporous manganese
oxides nanofibers prepared by electrospinning technique-
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Abstract: The electrospinning technique is used to synthesize several types of mesoporous manganese oxides, namely Mn2O3, Mn3O4, and hybrid manganese oxides. The as-spun nanofibers are heated at different temperatures from 500 to 1000 °C for 2 h. XRD analysis reveals that the Mn2O3 phase starts to form at 500 °C, whereas at 900 °C, Mn2O3 and Mn3O4 are co-existent and at 1000 °C, Mn3O4 is the sole phase. The mesoporous material’s behavior can be seen in all isotherms of the prepared manganese oxide nanofibers. The maximum surface area of 1306.98 m2/g is achieved for the sample calcined at 500 °C, which is one of the highest surface areas recorded for Mn2O3 as compared with the literature.
PubDate: 2023-05-12
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- Modification of ceramic membranes porosity using layer deposition of
kaolinite and palygorskite-
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Abstract: Ceramic membranes with high permeability can only be obtained in an asymmetric multilayer configuration with a macroporous support, which provides mechanical strength and lowers flow resistance. In this work, two clay soils, commercial kaolin (K) and a Moroccan natural material (P3), were used for the deposition due to their mineralogical composition rich in kaolinite and palygorskite respectively. The novel aspect of this work is the use of a 2-μm fraction of the two submentioned materials (K and P3) as a deposit on the cylindrical membrane supports comprised of anorthite, cordierite, and spinel powders to decrease the large pore size generated by the decomposition of the used pore-forming agent (Corralina Officinalis Algae). This latter showed an important and large granulometry due to the coarse grains of the algae. The layer deposition process on the elaborated membrane supports was dip-coated using different suspensions (solid ( wt.%), liquid (dispersant/distilled water ratio up to 3)). To determine the conditions for an optimum deposition efficiency, the effect of the clay concentration in the deposition suspensions and the immersion time (up to 6.5h) were discussed. It was found that the suspension containing 2% of clay with 2h of soaking time allows to increase adhesion strength which means that no cracks or defects were observed on the surface of the manufactured membranes. Decrease in the concentration of methylene blue that was used to prepare the filtrated solutions. Filtration tests were carried out and the absorbance of the filtered solutions was measured by UV-Vis and thus showed a significant decrease in their concentrations (0.021 mg/L).
PubDate: 2023-05-10
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- Preparation and chemical stability evaluation of new (Nd,An)2Zr2O7-SrZrO3
multiphase ceramics-
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Abstract: A series of new Nd(1-x)SrxZrO(3.5–0.5x) (0 ≤ x ≤ 1) multiphase ceramic waste forms, which can simultaneously immobilize An and Sr (with Nd3+ simulating An3+), were synthesized in situ by a sol-spray pyrolysis method. These multiphase ceramics are composed of a cubic pyrochlore phase Nd2Zr2O7(NZO) and an orthogonal perovskite phase SrZrO3(SZO) without any impurities. The content of the two phases can change regularly with the change of x. Nd and Sr can occupy the ceramics’ most stable lattice sites. The measured density of multiphase ceramics can reach more than 88% of the theoretical density. At the same time, the leaching rates of target Nd, Sr and Zr elements reached ~ 10−5 g·m−2·d−1, ~ 10−3 g·m−2·d−1, and ~ 10−7 g·m−2·d−1 at 90 ℃ and deionized water for 72 days, respectively, which shows that the multiphase ceramics had strong leaching resistance. The experimental results confirm that the new multiphase ceramics can immobilize An and Sr simultaneously and separately, and they have high chemical stability and strong adaptability to waste components. The multiphase ceramics is expected to be an ideal candidate waste form for An and Sr.
PubDate: 2023-05-10
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- Effects of CaO addition on the properties and microstructure of low-grade
bauxite-based lightweight ceramic proppant-
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Abstract: Corundum-mullite ceramic proppant was prepared by granulation and sintering with low-grade bauxite as the main raw materials and CaO as the additive mineralizer. The bulk density, breakage ratio, phase composition and microstructure of the ceramic proppant were characterized and studied. The results show that the bulk density and the breakage ratio of the ceramic proppant firstly increased and then decreased with the increase of CaO content. When the CaO content was 2 wt%, the ceramic proppant had the optimal performance, in which the bulk density was 1.52 g/cm3 and the breakage ratio was 8.2% under 52 MPa after sintering at 1440 ℃. It was found that the anorthite phase was formed in the ceramic proppant when the content of CaO was 2 wt%, which inhibited the growth of the secondary mullite crystals by consuming SiO2 and promoted the formation of corundum crystals, thus improving the strength and decreasing the breakage ratio of the ceramic proppant.
PubDate: 2023-05-09
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- A facile ball-milling method to combine carbon nanotubes and commercial
TiO2 towards nitrogen oxide photocatalytic removal-
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Abstract: Traditional TiO2 semiconductor is a promising photocatalyst. However, the extended application of this material for nitrogen oxide (NO) removal under sunlight conditions is becoming an emerging topic in materials science. Combining and modifying TiO2 with carbon materials such as carbon nanotube (CNT) towards applying a promising photocatalyst for gas pollution treatment have received much more significant attention. Herein, we combine and optimize CNT and commercial TiO2 by a ball-milling method towards a better photocatalyst in solar light driven. The analysis results indicated the existence of spherical TiO2 particles with an average diameter of 80–100 nm and CNT with a length and diameter of several nanometers and approximately 8–10 nm in the composites. The photocatalytic NO evaluation under a natural environment simulation model indicates that 0.7%wt CNT in CNT/TiO2 composite (0.7CT sample) achieves the most excellent photocatalysis. The CNT/TiO2 composites also express high stability. However, the CNT/TiO2 composite still has a limitation with a high NO to NO2 conversion yield.
PubDate: 2023-05-09
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- Synthesis and characterizations of ferrite/polypyrrole composites for
electromagnetic shielding-
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Abstract: Ferrite polymer composites, a seamless fusion of magnetic and polymeric properties, embody both strength and flexibility, paving the way for a new era of innovative applications. Composite nanomaterials of BaFe2O4/polypyrrole were synthesized by combining spinel ferrites and polypyrrole (PPy) by standard ceramic method. The X-ray diffraction (XRD) measurements revealed that the spinel ferrites were uniformly distributed throughout the single-phase PPy-matrix. Because PPy is amorphous, the size of the crystallites in nanocomposites grew as the amount of spinel ferrite in the matrix went up. At higher frequencies, the dielectric loss of the composites decreases due to reduced polarization effects. The addition of nanoparticles to the PPy matrix made the conduction channel narrower, leading to increased activation energy and resistivity. The magnetic properties of the composites were enhanced by adding ferrite components. The obtained results indicate that the prepared composites may be a potential candidate for EMI shielding applications.
PubDate: 2023-05-03
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- Effect of synthesis method on the structural and optical properties of
Ca2V2O7-
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Abstract: Vanadium oxides have been extensively studied once vanadium oxidation states provide unique characteristics, allowing applications in several areas, such as light-emitting devices and photocatalysts. The solid-state reaction is the oldest route for synthesizing ceramic compounds; however, it includes a lack of homogeneity and purity in the final material. In contrast, the Pechini method enables excellent particle size and morphology control, together with high-purity materials, at lower temperatures and reaction times. Although synthesis strongly influences the material’s applicability, few studies have compared these methods experimentally. The present work expects to contribute to understanding the differences between solid-state reaction and Pechini routes in the obtention of CaV2O7 and how it impacts the final characteristics of the material. The synthesis was carried out using the solid-state method and modified Pechini in a temperature range of 650–850 °C. The powders possess a particle distribution as a function of temperature. The material shows an absorbing performance of about 500 nm, with a band gap of around 3 eV, slightly higher for the solid-state reaction route, as it is closely related to the size and purity of the particles. In summary, the results suggest that the solid-state reaction requires a higher temperature to obtain a higher purity material, while the Pechini method provides the same purity at all temperatures applied, together with a more homogeneous morphology, which shows to be a promising photocatalyst material capable of decolorizing 40% of a methylene blue solution in 120 min where it can play an important role for wastewater treatments.
PubDate: 2023-05-02
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- SiBOC foams from methylvinylborosiloxane using urea crystals as a pore
template and ethylenediamine as a gelling agent-
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Abstract: A simple urea crystal templating method is reported for the preparation of SiBOC ceramic foams, with rectangular rod-like pores, from methylvinylborosiloxane (MVBS) preceramic polymer solution. Pastes of urea crystals in concentrated MVBS solution were filled in open rectangular mold and set by cross-linking of MVBS using ethylenediamine (EDA) at room temperature. The cross-linking is due to the formation of adduct between electron-deficient boron in the polymer backbone and lone pair of electrons in amino groups of EDA. The gelation time of 60 wt.% MVBS solution in ethanol is modulated in the range of 240 to 3.25 h using EDA concentration in the range 0.33 to 10 wt.%. The gelled body is water-washed to leach out urea, followed by inert heat treatment at 1500 °C to produce SiBOC foam. The SiBOC ceramic foams of density 0.739 to 0.215 g cm−3, compressive strength 2.75 to 0.207 MPa, and thermal conductivity 0.262 to 0.073 W m−1 K−1 were achieved with urea concentrations of 50 to 88 vol.%. SEM micrographs show rectangular rod-like pores resulting from the urea particle template, which increases with an increase in urea concentration. XRD and TEM confirm SiBOC as amorphous, with the presence of a few nanocrystals of β-SiC and turbostratic carbon layers. The low thermal conductivity, excellent oxidation resistance, and reasonably high compressive strength make the prepared foams suitable candidate for high temperature thermal protection in aerospace.
PubDate: 2023-04-24
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- Synthesis, phase stability and chemical leaching behavior of Nd-doped
CaTiO3 perovskite ceramics for radioactive waste immobilization-
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Abstract: Perovskite ceramic is a component of the SYNROC polyphase waste form, designed to immobilize trivalent minor actinides and radioactive Sr resulting from the reprocessed nuclear fuel. In this paper, the ceramics Ca(1-x)Nd2x/3TiO3 (CNTx) (x = 0.00, 0.225, and 0.525) are synthesized by solid-state reaction method using Nd(III) as a trivalent actinide substitute. The structure/microstructure of the synthesized ceramics is characterized by XRD, Raman spectroscopy, and SEM. The XRD investigations indicated the obtention of a perovskite structure throughout the studied neodymium concentrations range, with a smaller amount of TiO2. Rietveld structural refinements show an orthorhombic symmetry with Pbnm space group for all the studied compositions. The Nd atoms are completely dissolved into the twelvefold coordinated calcium site of the orthorhombic perovskite structure. As Nd content increases, Raman bands broaden due to the distortion of TiO6 octahedra and disordered arrangements of Ca and Nd in the lattice site. In addition, aqueous durability tests were carried out using the MCC-1 type leach testing. Chemical durability of the samples is shown to be dependent on the ceramic composition. The normalized release rates of Ca, Nd, and Ti from the studied ceramics indicated that Ca was the most dissolved element in the leachates; the other two elements (Nd and Ti) revealed extremely low release rates.
PubDate: 2023-04-24
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- A 3D cellular automata model for grain growth in ceramic materials
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Abstract: Based on the grain growth driving force theory of grain boundary energy and grain boundary curvature, a theoretical model of grain growth in a three-dimensional (3D) cellular automata (CA) is established. The effects of different neighbor types, different ranges of orientation values, and random cellular impurities on the 3D CA microstructure model are studied. Then, the simulation results are compared and verified through the sintering experiment of ceramic materials. The results show that removing the impurity grains with one cell at the later simulation stage can minimize the influence of impurity grains on the simulation results. The 3D CA model simulation results show that the maximum orientation value Q = 400 under the 26-neighbor type is very close to the microstructure of Al2O3/TiN ceramic material, which can better represent the process of ceramic material grain growth.
PubDate: 2023-04-21
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- Wear and high-temperature stability of TiCN-WC-Co-Cr3C2-HfC-Si3N4 cermets
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Abstract: This work reports the wear and high-temperature stability of TiCN-WC-Co-Cr3C2-HfC-Si3N4 cermets developed by spark plasma sintering (SPS). The addition of Si3N4 in the range of 5 wt. % to 15 wt. % in TiCN-WC-Co-Cr3C2-HfC cermet composition showed hardness of the cermets in the range of 10.2±0.05 to 11.7±0.05 GPa. Among the three cermets developed, 60TiCN-15WC-10Co-5Cr3C2-5HfC-5Si3N4 possessed a hardness value of 11.7±0.05 GPa and fracture toughness value of 15.1±3.5 MPa√m. The wear behaviour of the cermets was studied using a pin-on-disc machine with cermets as a pin on EN 31 steel counter disc material with three different sliding velocities in the range of 0.23–0.35 m/s, at a constant normal load of 20 N for a duration of 5 min. 60TiCN-15WC-10Co-5Cr3C2-5HfC-5Si3N4 cermet showed a high wear resistance at all the three sliding velocities compared to the other cermet composition. High-temperature stability of the cermets was assessed by heating the cermet samples to 600 °C, 800 °C and 1000 °C and holding them for about 4 h followed by cooling within the furnace itself. All the three cermets were stable up to 800 °C. Cermet 60TiCN-15WC-10Co-5Cr3C2-5HfC-5Si3N4 showed less affinity for oxidation after heating, and hence, it has good thermal stability than other cermet compositions.
PubDate: 2023-04-19
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- A comprehensive archaeometric analysis of a novel special organic finding
in a glass unguentarium: NMR, FT-IR, SEM/EDX-
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Abstract: In this study, systematical analyses were employed to determine that which period the historical artifact belonged, and evaluations were based on the glass-making technology of the period. In addition, since organic substances were carried in these glass bottles, they are likely to be the medicine or ornaments at that time; by using recently developed techniques as NMR-SEM–EDX and interpret them in the correct way, it was possible to predict what the yellow oily looking organic substance might be in. As the mouth of the glass bottle is completely closed with clay, the characterization of this organic material was made on the clay sample taken from the underneath of the environment without damaging the historical artifact. The trace organic matter residues on the clay were isolated and characterized by NMR spectrometry; this sample was characterized with FT-IR. Finally, the surface morphology of the clay–oil mixture was examined morphologically with SEM, and with EDX, elemental analysis was performed. In the results obtained, it was concluded that the organic material in the historical artifact could be olive oil with a high content of palmitic acid. With this study, the content of the artifact could be clarified by making a structural examination of the remains without damaging the historical artifact.
PubDate: 2023-04-19
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- Microstructure and properties of hierarchical porous ZrO2/Al2O3 ceramics
prepared by gel-foaming method-
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Abstract: Hierarchical porous ZrO2/Al2O3 ceramics with controllable pore structure were fabricated by gel-foaming method using nontoxic sodium alginate as gelling agent. Both the rheological property of ceramic slurry and the curing mechanism of gelatin system were studied. The effects of ZrO2 content and sintering temperature on the pore structure and properties were also investigated. The three-dimensional net structure forms between calcium ion and sodium alginate molecule; then, the ceramic powder can realize in situ solidification. The porosity changes from 33 to 74% with different ZrO2 content and sintering temperature. The macropores can be controlled through adjusting the foaming agent and ZrO2 contents. The mesopores are mainly regulated by sintering temperature. The porosity and pore structure can be tailored through optimizing the gel-foaming and sintering process parameters. The sintering temperature has important influence on the mechanical properties. The porous ceramics with 25% ZrO2 content sintered at 1550°C shows the highest compressive strength of 130MPa. The mechanical properties are improved with the micro-crack toughening and phase transformation mechanisms of ZrO2 phases. Hierarchical porous ceramics with more inter-connective pores, high specific surface area, and suitable strength are promising for filtration and catalyst support applications.
PubDate: 2023-04-17
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