Ceramic Bodies Research Articles

High-performance aluminum nitride made by Vat photopolymerization through optimization of resin refractive index and plasticizer content

In this study, we evaluated the effects of three resins with different refractive index on the viscosity and curing behavior of aluminum nitride (AlN) ceramic suspensions. Our findings indicate that the viscosity of the AlN suspensions increased with the concentration of polyethylene glycol o-phenylphenyl ether acrylate (OPPEA). Conversely, the viscosity decreased with increasing concentrations of cyclic trimethylolpropane formal acrylate (CTFA) and ethylene glycol phenyl ether acrylate (PHEA). Regarding the curing behavior, the AlN ceramic suspension prepared with OPPEA exhibited the largest cure depth and excess width, whereas the suspension prepared with CTFA had the lowest cure depth and excess width. Further analysis of the sensitivity and critical energy revealed that the suspension containing OPPEA demonstrated the highest sensitivity in the vertical direction and the lowest sensitivity in the horizontal direction. This implies that the smallest critical energy is in the vertical direction, and the largest critical energy is in the horizontal direction. Additionally, an increase in the content of the plasticizer dibutyl phthalate (DBP) was beneficial for reducing cracks in the AlN ceramic debinding bodies. Finally, high-performance AlN ceramics were produced, exhibiting a relative density exceeding 98 %, a bending strength of 470.39 ± 6.5 MPa, and a thermal conductivity of 163.45 W/m·K.

Design and performance of lightweight high–temperature resistant microwave penetrating foamed ceramics

To develop lightweight microwave penetrating materials capable of operating at high temperatures, the technical potential of preparing foamed ceramics (FCs) from a simple material system using boron nitride (BN) as the foaming agent was studied. The preparation mechanism of the FCs is that the oxidation–derived nitrogen from BN blows up the molten ceramic body during sintering. The FCs sintered at 1000 °C from the material system containing 0.3 wt% ferric oxide have a uniform pore structure with a mean pore diameter of 1.0 mm, high total/closed porosities of 82 %/81 %, a low density of 0.45 g/cm3, and an adequate compressive strength of 6.9 MPa. The high porosity and simple composition allow the FCs to have a low permittivity of 2.09+j0.024 in the X–band and over 95 % penetration of incident microwaves in the 8.0–18.0 GHz frequency range. The FCs are potentially lightweight, moisture resistant and thermal insulating due to their low density, high closed porosity, and uniform pore structure, which are expected to be an excellent high–temperature microwave penetrating material based on their retention of pore structure and physical–mechanical properties at 800 °C.

Ceramic floor tiles with yellow pigment from Kievan Rus’: A technological study

Colored glazed ceramic tiles were widely used for paving floors of the main buildings, mostly Orthodox churches, in the Kievan Rus’ (10th-13th centuries AD). The production of ceramic floor tiles was localized near the site of construction, and the date of production can be attributed to the date of construction or renovation of the church. Therefore, the study of glazed tiles makes it possible to determine the local and chronological features of their production technology.. Local production technology in Ancient Rus' was studied using thirteen yellow glazed ceramic tiles from six cities (Kiev, Galich, Polotsk, Vladimir-Volynsky, Pereslavl-Zalessky and Novgorod). Also, two samples were selected from churches in Polotsk, Vladimir-Volynsky and Vyshgorod at different times of construction or renovation to study chronological variations in tile production technology. Chemical compositions and crystalline phases of yellow glaze and ceramic body have been analyzed by X-ray diffraction, Raman and X-ray fluorescence spectroscopy. In all cases, samples of ceramic tiles were glazed with high-lead silicate glass, and lead tin yellow type II (PbSn1-xSixO3) was used as a pigment. Local production technology in Ancient Rus' was studied using thirteen yellow glazed ceramic tiles from six cities (Kiev, Galich, Polotsk, Vladimir-Volynsky, Pereslavl-Zalessky and Novgorod). Also, two samples were selected from churches in Polotsk, Vladimir-Volynsky and Vyshgorod at different times of construction or renovation to study chronological variations in tile production technology. Most likely, the glaze layer on the ceramic tile was formed using pre-synthesized glass; this technology differs from the conventional technology for pottery, uses lead oxide or a mixture of lead oxide and quartz. Data on the chemical composition of yellow lead glazed tiles dating from the 10th-13th centuries AD can be used to determine the region of glazed ceramic production.

Proton conductivity of Li+–H+ exchanged Li7La3Zr2O12 dense membranes prepared by molten long-chain saturated fatty acids

Alkali-proton exchange throughout ceramic dense bodies becomes possible using molten long-chain saturated fatty acids. As a case study, 91% Li+–H+ exchange of Al-doped cubic garnet-type Li7La3Zr2O12 dense membranes was demonstrated in this work.

Examining the properties, behaviour in firing and potential application of coal mine overburden for stoneware ceramics

Purpose. A binary mixture of a ceramic body was studied, incorporating overburden from a coal mine site in Bontang, East Kalimantan, Indonesia. This overburden material has been tested for the manufacture of stone-ceramic body. Methods. The initial characterization of overburden materials includes testing the chemical composition by XRF analysis and mineral content by XRD analysis on raw materials and overburden exposed to high temperature. The composition of ceramic specimens is a mixture of 85% overburden material and 15% fine sand. Firing temperatures in the range of 900-1100°C were applied to the ceramic body specimen. Then, ceramic properties, such as physical color, plasticity, shrinkage, water absorption and density were analyzed. Findings. The results show that the ceramic specimen experiences densification when exposed to high temperature in this range, which in turn contributes to low water absorption and high flexural strength. This ultimately results in low water absorption below 1.0% at 1100°C, which is favorable for stoneware type of ceramics. The mechanical properties of specimen at 1000°C is in accordance with stoneware body standard. In addition to this, it is believed to be more energy efficient, since the low firing temperature is sufficient to achieve the stoneware specification. Originality. The binary clay-based ceramic have been tested using coal mine overburden and river sand with a high Fe2O3 content. Together with the presence of alkali oxides and calcium in the raw materials, this can potentially reduce the use of fluxing agent. A comprehensive study has been conducted on the characteristics, firing effect and application of stoneware. Practical implications. Some ceramic prototypes from this result were also made using a rotary technique and heated in this temperature range. Since overburden is generally considered to be backfill material, the selective clay material application for ceramics can provide the potential to stimulate local product innovation by utilizing easily available overburden materials.

Fired electrical porcelain scrap (chamotte waste) recycling and reuse as an alternative raw material for sustainable porcelain stoneware production

The development of new sustainable ceramic formulations that incorporate industrial waste is a practice that meets the efficiency and sustainability criteria that today's society demands for an industry with high energy and non-renewable mineral sources consumption. In this research, fired electrical porcelain scrap (chamotte waste) was recycled and reused in the porcelain stoneware manufacture, partially replacing the quartz and feldspar from the triaxial system at 5, 10, 15, 20, and 30 wt%. The experimental samples were obtained after uniaxial pressing of ceramic mixture powders at 30 MPa and firing at 1260 °C following a fast-firing process (90 min cold to cold). The technological properties were studied by bulk density, apparent porosity, linear shrinkage, water absorption, cold crushing strength, and Vickers microhardness. The microstructural aspects and the amount of crystalline and amorphous phases in the ceramic bodies were analyzed by scanning electron microscope and X-ray diffraction, respectively. The best technical characteristics were achieved with the incorporation of 15 wt% of chamotte in the new ceramic formulations, yielding a density value of 2.41 g/cm3, and percentages of linear shrinkage and water absorption of 11.2 and 0.08 %, respectively, as well as mechanical resistance of 314.94 MPa and microhardness of 7.07 GPa. The mechanical resistance achieved by the experimental sample containing 15 wt% of chamotte waste means six times the value obtained by the control sample (0 wt% of chamotte addition) and was attributed to a higher mullite phase content and well-dispersed crystals (primary and secondary mullite) in the ceramic body. The results suggest and advance in the design and development of a best-performance porcelain stoneware materials elaborated by a sustainable and ecological route.

Multiphysics and geometry-based modeling of incorporating mass transport networks in ceramic green bodies to improve thermal debinding

Binder-based ceramic manufacturing is an integral technique for fabricating intricate ceramic structures. These structures can be formed (e.g., through injection molding) or additively manufactured (e.g., extrusion-based 3D printing). However, the debinding process poses a significant challenge, due to the time for binder removal increasing with the square of the part thickness, and excessive pressure buildup that can lead to cracks in the part. In this study, we explore the use of mass transport networks to accelerate debinding and reduce pressure buildup. We employ two modeling approaches: multiphysics and geometry-based modeling. The results indicate that the addition of appropriately selected mass transport networks can reduce the maximum pressure to below the critical pressure. The binder diffusion rate increases due to the network, enabling faster debinding times. This innovative approach enables faster processing and successful fabrication of larger structures, offering significant energy and cost savings while expanding design possibilities. Network design can be validated and optimized through modeling and incorporated via additive manufacturing.

Diopside-like based ceramics prepared via one-step sintering of extracted titanium slag and coal fly ash

Diopside-Like based ceramics as the main crystalline phase (expressed as ‘Diopside’) were prepared via one-step sintering using extracted titanium slag (ETS) and coal fly ash (CFA) as raw materials. The effects of CFA content and sintering temperature on the crystal phase composition, microstructure, properties and crystallization kinetics were studied by X-ray fluorescence, X-ray diffraction, scanning electron microscopy, and inductively coupled plasma emission spectrometry. According to the findings, the addition of CFA supplemented the deficiency of Si and Al in ETS and balanced the Ca/Al/Si molar ratio in the system. Moreover, at the CFA doping of 20 %, melilite was gradually transformed into ‘diopside’ at 800–1100 °C that further remained stable at 1160–1200 °C. ‘Despite’ the fact that the crystallization activation energy increased and the Avrami index was at its lowest level (1.75), the crystallization temperature was reduced, whereas the crystallization rate increased, causing the ceramic body and surface to crystallize and thereby improving the properties of ceramics. Sintering at 1180 °C for 1 h resulted in ceramics with ‘diopside’ as the primary crystal phase composition. The water absorption, linear shrinkage, bulk density, bending strength, and acid resistance were respectively 1.3 %, 13 %, 2.89 g cm−3, 141.8 MPa, and 97.36 %. Finally, ‘diopside’ possessed the higher acid resistance than melilite and anorthite.

Improvement of mechanical properties of ceramic green body and fired body by aging of inorganic binder in ceramic slurry for 3D printing

Fabrication of ceramic bodies with complex structures via photopolymerization-based 3D printing with minimal deformation during the inevitable heat treatment necessitates the development of a photopolymerizable ceramic slurry. This study prepared a photocurable slurry using a photocurable resin and particles coated with an inorganic binder. The condensation efficiency of the inorganic binder was improved by applying an aging process to the green bodies, which in turn improved the fracture strength and enhanced the glass conversion efficiency of the particles during the subsequent firing process. The exceptional mechanical properties of the fired bodies fabricated using inorganic binder-coated starting particles can be attributed to the glass matrix formed between the particles rather than the particle-to-particle interfaces. We believe this study demonstrates the feasibility of fabricating ceramic bodies with minimal shrinkage and distortion compared to conventionally sintered bodies.

Комплексный анализ тканей амфор и клейм Фасоса по данным фазового и элементного состава

The paper presents the results of studying of the Thasian amphorae fabrics of the second quarter of the 5th — end of the 4th century BC, whose belonging to the island’s products was established on the basis of morphological features of vessels and, in some cases, due to the presence of stamps. A complex approach was used to study amphorae fragments, including the methods of integral (X-ray phase analysis, inductively coupled plasma mass spectrometry) and local (electron microscopy) characterization of the structure and composition. The proven set of methods made it possible to obtain reliable data on the mineral (phase), basic and trace chemical composition of the samples, as well as to study the composition of the fabric base of the samples ceramic body, excluding the influence of mineral impurities and leaners. The analysis of the experimental results allowed to group the objects into separate groups in accordance with the features of the mineralogical and elemental composition. Based on the comparison of the characteristics of these groups with geological and archaeological information about the island of Thasos, the authors advance a hypothesis with a clarification of the origin of Thasos amphorae, namely, their manufacturing in workshops on the eastern and southern coasts of the island.

Introduction of the potter’s wheel as a reflection of social and economic changes during the La Tène period in Central Europe

This study focuses on the introduction of pottery-forming methods employing rotational motion in relation to social and economic conditions and their transformations during the La Tène period in Central Europe. It explores the diversity of technological practices on a broader geographical scale in several regions of the Czech Republic with various demographic, social, and environmental conditions during this period. The study is based on the idea that a technological process is a cultural trait whose adoption is the result of a cultural selection. These interactions are facilitated by the performances of the technological process and its products. The technological analysis relies on a recently developed quantitative analytical technique based on calculating the orientation of components of the ceramic body supplemented by qualitative classification of diagnostic features observed on X-ray images and CT reconstructions. By applying the methodology to an extensive collection of pottery samples, we have obtained a robust picture of the adoption and spread of different variants of the application of rotational motion. Based on this evidence, we proposed evolutionary scenarios that show the unique interplay of the performances of the individual variants of this general innovative idea with specific local socio-cultural conditions.

Bio-inspired nacre-like zirconia/PMMA composites for chairside CAD/CAM dental restorations

ObjectivesTo introduce a versatile fabrication process to fabricate zirconia/PMMA composites for chairside CAD/CAM dental restorations. These zirconia composites have nacre-like lamellar microstructures, competent and tooth-matched mechanical properties, as well as crack resistance behaviours. MethodsBi-directional freeze casting was used to fabricate ceramic green bodies with highly aligned lamellar structure. Pressure was then applied to control the ceramic volume fraction. PMMA was infiltrated into the ceramic scaffold. Mechanical tests including 3-point bending, Vickers hardness, and fracture toughness were performed on the composites. The machinability of the composites was also characterised. ResultsTwo types of nacre-like zirconia/PMMA composites, i.e., 3Y-YZP/PMMA and 5Y-PSZ/PMMA composites were fabricated. The microstructure created was similar to the ‘brick and mortar' structure of nacre. Excellent flexural strength (up to 400 MPa and 290 MPa for 3Y-TZP/PMMA and 5Y-PSZ/PMMA composite, respectively), tuneable hardness and elastic modulus within the range similar to enamel, along with improved crack-resistance behaviour were demonstrated on both zirconia composites. In addition, both zirconia/PMMA composites showed acceptable machinability, being easy to mill, as would be required to produce a dental crown. SignificanceNacre-like zirconia/PMMA composites therefore exhibit the potential for use in the production of chairside CAD/CAM dental restorations.

Composition of Various Percentages of Terracotta Clay as Colourant Glaze

Terracotta is valuable for its mineral content, which produces pigments for coloring ceramic bodies and glazes. Unlike commercial colors, terracotta's natural minerals make it unique. This study explores the potential use of local terracotta clay in transparent glaze formulations. Methods like clay powder percentages, X-ray diffraction, X-ray fluorescence tests, electron scanning, and microscope analysis (SEM) are used to examine the clay elements' morphology and structure. The addition of terracotta clay powder in proportions (20-50%) rendered the glaze translucent. Samples were applied on porcelain and fired at gloss temperatures (1200°C). The result colors were glossy, smooth, and creamy, with no defects. Keywords: Terracotta, colorant, glaze, percentage

Structural evolution and chemical durability of uranium-doped high-entropy pyrochlore

The high-entropy ceramic solidified body ((LaPrEuGdYb)yUx)2Zr2O7+δ (y = (1−x)/5, x = 0.05, 0.10, 0.15, 0.20, 0.25) was prepared by immobilizing uranium (U) on the A-site of the pyrochlore in this study. The phase composition and evolution of solidified body were determined by XRD, Raman and SEM analysis. The phase of (LaPrEuGdYb)yUx)2Zr2O7+δ ceramic was varied with U doping amounts: a dual-phase of pyrochlore and fluorite with no U doping. A single-phase pyrochlore with U doping amounts from x = 0.15 to x = 0.20, and the U3O8 phase was precipitated at doping levels above x = 0.25. The solid solution limit for high entropy pyrochlore in relation to uranium is roughly x = 0.2. The results should be linked to the increase in configurational entropy and the variation of U valence in the ceramic bodies, as evidenced by XPS. The normalized leaching rate of U from high-entropy ceramic waste forms (x = 0.20) was about 1.65 × 10−5 g/m2⋅d after 42 d leaching. It performed well in the leaching tests. Our study is expected to provide candidate materials for solidifying complex high-level radioactive waste (HLW).

W kwestii techniki wykonania i szkliwienia wczesnośredniowiecznych pisanek-grzechotek ze Śląska.

The article concerns early medieval egg-shaped rattles from the area of Silesia. First of all, the issue of how they were made and glazed is studied. The issues of the origin of these products and their role in the culture of ancient societies, as problems repeatedly raised by other researchers, is treated marginally. Macro- and microscopic observations, experimental studies, as well as the results of analyses of the chemical composition of glazes and petrographic tests of ceramic bodies were used to study the technology of making eggs-shaped -rattles. On their basis, the probable process of their formation and glazing was reconstructed. While the making of the ceramic base did not require extraordinary skills, the glazing and decoration of the rattles took place in several stages, requiring knowledge of advanced pottery techniques. For their decoration, a specific category of glaze was used, namely high-lead non alkali glass.

Enhancing rheology and physico-mechanical properties of ceramic slurries: Effect of the addition of various types of deflocculants

This study investigated the impact of various types of deflocculants with different chemical composition on ceramic slurries rheology. Organic and inorganic plasticizers were substituted for sodium silicate plasticizers in floor tile recipes, and their effects on rheology were assessed. The interactions of these materials with the silicate and ceramic slurry in terms of synergistic, antagonistic, and additive properties were then determined. In addition, the physico-mechanical properties of the ceramic bodies obtained using commercial plasticizers were investigated. Microstructural analysis using scanning electron microscopy (SEM) and mineralogical properties using x-ray diffraction (XRD) were performed. Results revealed that the addition of silicate to the slurry had a synergistic effect on rheology, reducing second viscosity to 50 s with a thixotropy ratio of 22%. Moreover, the flexural strength of the sample with 1% silicate addition increased by 13.6%, indicating positive effects on physico-mechanical properties. SEM analysis indicated the formation of a more uniform dispersion of particles with silicate addition. These findings suggest that incorporating silicate into ceramic slurries can effectively enhance both rheology and physico-mechanical properties, holding significant implications for ceramic tile and product manufacturing.

Investigating laser sintering in Y3Al5O12 ceramics

This study investigates the experimental parameters of the laser sintering process of Y3Al5O12 ceramics. Ceramic powders were produced using the polymeric precursor method and sintered using a CO2 laser as the heating source. The samples were characterized using differential thermal analysis, thermogravimetric analysis, X-ray diffraction, and scanning electron microscopy techniques. The results showed that parameters such as powder calcination temperature, dwell time, and laser power density rate are crucial in obtaining dense ceramic bodies. Furthermore, developing and using a sample holder made of the same material composition to be sintered showed significant advances in the laser sintering process.

Fabrication of β-TCP/ Akermanite composite scaffold via DLP and in-situ modification of micro-nano surface morphology for bone repair

Although β-TCP bioceramics possess favorable biocompatibility and bioactivity, their inherent brittleness restricts further applications. In this study, we aimed to enhance the mechanical performance and biocompatibility of β-TCP by incorporating 15% Akermanite (AK) into the structure. The fabrication process involved the use of digital light processing (DLP) technology to fabricate ceramic green bodies, followed by high-temperature debinding and sintering to obtain the ceramic scaffold. Subsequently, we employed an in-situ growth technique to create micro/nano surface topography on the scaffolds, facilitating synergistic regulation of cell behavior in conjunction with the controlled release of bioactive agents. Scanning electron microscopy (SEM) revealed that the addition of AK enlarged the grain size and reduced the number of micropores in the composite scaffold. Furthermore, after the in-situ growth treatment, a significant increase in micro/nano surface features was observed. Mechanical testing demonstrated that the incorporation of AK effectively improved the mechanical properties of the composite scaffold, resulting in an increase in strength of approximately 20%. Cell experiments indicated that AK supplementation further enhanced the material's cell compatibility, and the presence of micro/nano structures effectively promoted cell adhesion, proliferation, and expression of osteogenic genes. Consequently, we propose a strategy for fabricating porous bioceramics that stimulate bone growth, exhibit high strength, and ameliorate the degradation microenvironment. This approach opens up promising avenues for future applications in bone tissue engineering.

Optimizing photocuring properties of ceramic slurry for 3D printing of ceramic membranes

The utilization of 3D printing for fabricating ceramic membranes has garnered increasing attention in recent years. However, the precise preparation of ceramic slurries tailored for this purpose remains an area requiring more systematic research. This paper delves deeper into the photo-curing characteristics of ceramic slurries characterized by high solid content and low viscosity. Employing a mask-curing experimental system, the study investigates the impact of photoinitiators and additives, such as triethanolamine and tartrazine, on the photo-curing performance. Quantitative analysis is carried out, considering various parameters, including curing depth, curing broadening, broadening depth, critical energy, and curing sensitivity. By incorporating diphenyl(2,4,6-trimethylbenzoyl)phosphine oxide (TPO), triethanolamine (TEOA), and tartrazine at optimized concentrations of 0.1 wt%, 1.5 wt%, and 1.0 wt% respectively, the broadening depth increases significantly, exceeding 200 μm. This effectively meets the curing depth requirements for 3D printing tasks. Consequently, the printed ceramic green body exhibits excellent shape retention, surface flatness (Ra < 0.9 μm), as well as ample strength and toughness. These characteristics provide a solid foundation for the subsequent preparation of high-performance ceramic membranes.

Morphologic Analysis of Zirconia Ceramics: Effect of Different Surface Treatments.

To investigate the effects of airborne-particle abrasion and nanosilica (nano-Si) infiltration treatment on the surface characteristics of dental zirconia. A total of 15 unsintered zirconia ceramic green bodies (10 × 10 × 3 mm) were divided into three groups (n = 5): Group C, no treatment after sintering; Group S, airborne-particle abrasion with 50-μm aluminum oxide particles after sintering; and Group N, infiltration of nano-Si followed by sintering and hydrofluoric acid (HF) etching. The zirconia disks' surface roughness was analyzed by atomic force microscopy (AFM). The surface morphology of the specimens was analyzed using scanning electron microscopy (SEM), and the chemical composition was analyzed by energy-dispersive x-ray (EDX). Data were statistically analyzed by the Kruskal-Wallis test (P < .05). Zirconia surface treatments by infiltration of nano-Si, sintering, and HF etching showed multiple changes in the surface features. The surface roughness of Groups C, S, and N were 0.88 ± 0.07 μm, 1.26 ± 0.10 μm, and 1.69 ± 0.15 μm, respectively. The surface roughness of Group N was significantly higher than that of Groups C and S (P < .05). EDX analysis showed peaks that corresponded to silica (Si) after infiltration with colloidal Si that disappeared following acid etching. Infiltrating nano-Si increases the surface roughness of zirconia. The formation of retentive nanopores on the surface potentially improves the zirconia-resin cement bonding strengths.