High Temperature Ceramic Materials Research Articles

STUDY OF EXCHANGE REACTIONS IN THE SrO-BaO-Al2O3 -SiO2 SYSTEM

Scientific research in the field of nanotechnology and composite materials for aviation and space technology contributes to the creation of new types of radio-transparent materials with improved properties. The need for these materials is especially growing in conditions of high temperature, high speed and aggressive external environment, where traditional polymer or composite materials cannot provide the necessary level of key properties. Ceramic materials made on the basis of target phases of the SrO-BaO-Al2O3 -SiO2 system have low dielectric properties and are quite promising for use in various fields where high transparency for electromagnetic waves with minimal losses is important. In this regard, a more detailed study of its subsolidus structure is relevant. This article deals with the flow of exchange reactions of the type аА+бВ = сС+дД in the volume of the SrO-BaO-Al2O3 -SiO2 concentration tetrahedron. The paper presents the results of Gibbs free energy calculations for exchange reactions in the considered system. The temperature intervals for the existence of separate combinations of phases are indicated and the formed elementary triangles are graphically presented. Based on the results of theoretical studies, it was established that in the SrO-BaO-Al2O3 -SiO2 system there is a possibility of five exchange reactions of the type аА+вВ = сС+дД. It was found that BaAl2Si2O8 – SrAl2O4 and Sr3Al2O6 – Ba2SiO4 anodes are present in the temperature range of 300...1700 K. The presence of a combination of "filled triangle" phases – Sr2Al2SiO7-2SrSiO3-BaSiO3 in the temperature range of 300...800 K was confirmed, and the existence of a combination of "filled circuit" phases – BaSiO3 – BaAl2O4 – Sr2Al2SiO7 in the temperature range of 1200...1700 K was confirmed. The discovery of this combination of phases makes it possible to expand the existing area in the experimental system for creating high-temperature ceramic materials. In turn, according to the obtained data of thermodynamic calculations, it was established that at temperatures below 1200 K, the target phases of the considered system, Ba2SiO4 and SrAl2Si2O8, do not interact with each other, and the reaction is thermodynamically disadvantageous.

Preparation method and industrialization of Ta-based ultra high temperature ceramic Tujia jar tea baking jar materials

The production materials of traditional Tujia jar tea often face problems such as poor high-temperature performance and poor durability. To improve the temperature resistance and durability of tea baking utensils, this study proposes a new type of TaC ultra-high temperature ceramic. TaC ceramics with excellent performance were prepared through powder metallurgy technology, including high-energy ball milling to ensure uniform mixing, followed by compression molding and high-temperature sintering. The test results demonstrated excellent mechanical properties, with a maximum depth of 948.67 nm and a contact depth of 954.45 nm, proving outstanding compressive and wear resistance. The hardness reached 21.4±0.5 Gpa, and the elastic modulus was 397.2±8.7 Gpa, both of which indicate its stability under high loads. In addition, the fracture toughness was 2.8±0.2 Mpa*m1/2. At a high temperature environment of 1000 °C, the oxidation rate constant of TaC ceramics was only 0.183 mg2 *cm−4 *h, which demonstrates its excellent high-temperature stability. The development of this TaC ceramic not only strengthened the traditional production process of Tujia teapots and tea roasting teapots, thereby improving the product’s service life, but also holds potential for other industrial applications that demand ultra-high temperature stability. These contributions provide new directions for the high-temperature application of ceramic materials and bring tangible economic and technological value to related industries.

Insight into the pyrolysis and gas generation behavior of silicomanganese slag and assessing its foaming abilities in foam glass ceramic

This paper proposes a novel route for the utilization of silicomanganese slag in the preparation of high-temperature foam ceramic materials, grounded in the unique characteristics of the slag. The phase evolution and gas generation mechanisms of silicomanganese slag was systematically investigated using thermogravimetric mass spectrometry (TG-MS), thermodynamic simulation, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). Foam glass ceramic with a density of 291 ± 8 kg/m3 and a compressive strength of 2.83 ± 0.07 MPa was prepared using silicomanganese slag as a foaming agent. This research indicated that manganese and sulfur in the silicomanganese slag are critical contributors to gas generation. Manganese in the slag oxidizes to dimanganese trioxide (Mn2O3) before reaching 1000 °C, and at temperatures between 1000 and 1200 °C, trivalent manganese (Mn3+) converts to divalent manganese (Mn2+) and enters the pyroxene crystal, releasing oxygen (O2). Sulfur in the slag, captured by divalent calcium (Ca2+), forms a more stable calcium sulfate (CaSO4) during heating and enriches the slag particle surface. As the temperature exceeds 1000 °C, Ca2+ gradually integrates into the pyroxene, prompting the release of sulfate decomposition products, forming sulfur dioxide (SO2) and O2. A small fraction of unreacted CaSO4 enters the glass phase, forming fibrous crystals that enhance the compressive strength of the foam glass-ceramic through fiber reinforcement. The outcomes of this work offer new insights into the high-value utilization of silicomanganese slag and enrich the understanding of gas generation mechanisms in Mn-based and S-based foaming agents.

Heat transfer and behavior of ultra high temperature ceramic materials under exposure to supersonic carbon dioxide plasma with additional laser irradiation

The behavior of the ultra high temperature ceramic material HfB2-SiC-C(graphene) under exposure to a supersonic carbon dioxide plasma, with and without the addition of laser irradiation, has been studied. The material was heated to 1750 °C in an inductively coupled plasma jet without laser irradiation. A temperature jump to 2190 °C was observed when additional ytterbium laser irradiation was applied to the surface. The spectral emissivity of the heated surface at wavelengths of 0.65 and 0.9 μm was studied. It was found that the spectral emissivity decreases as the material oxidizes. The heat flux to the surface of the heated material was measured and compared to the heat flux to a cold copper surface under the same conditions. Analysis of the surface of HfB2-SiC-C(graphene) material after exposure was performed. Differences in microstructure were detected between specimens exposed to carbon dioxide plasma with and without additional laser irradiation.

Effect of annealing temperature on the microstructure, dielectric, and microwave absorption performance of precursor blends derived ZrSiOCN ceramics

The ZrOC ceramic derived from polyzirconoxane (PZC) precursor, usually composed of ZrO2 and ZrC, is a high temperature ceramic material possessing great potentialities to be applied in harsh environments. However, the relatively high electrical conductivity of ZrC usually results in the limited electromagnetic wave absorption performance, and it's an effective way to adjust the relative complex permittivity of ZrOC ceramics by introducing SiCN ceramics with low dielectric properties. In this work, polyzirconoxane (PZC) and polysilazane (PSN) precursors were blended at the weight ratio of 1:1 firstly, then the blends were cured and pyrolyzed to prepare the ceramics composed of Zr compounds and Si-containing amorphous ceramics. As the annealing temperature rises, t-ZrO2, turbostratic carbon, and ZrC0.347N0.653 grains appear, and the real and imaginary parts of the permittivity gradually increase. It can be found that ZrC0.347N0.653 and free carbon form a typical core-shell structure when the annealing temperature is 1500 °C, and the as-obtained ceramic possesses remarkable microwave absorption ability. The minimum reflection loss is −22.7 dB at 12.02 GHz, and the value of effective absorption bandwidth is 1.65 GHz with a sample thickness of 2.0 mm.

Synthesis and Thermal Oxidation Resistance of Boron-Rich Boron-Carbide Material.

A boron-rich boron-carbide material (B4+δC) was synthesized by spark plasma sintering of a ball-milled mixture of high-purity boron powder and graphitic carbon at a pressure of 7 MPa and a temperature of 1930 °C. This high-pressure, high-temperature synthesized material was recovered and characterized by X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, Vickers hardness measurements, and thermal oxidation studies. The X-ray diffraction studies revealed a single-phase rhombohedral structure (space group R-3m) with lattice parameters in hexagonal representation as a = 5.609 ± 0.007 Å and c = 12.082 ± 0.02 Å. The experimental lattice parameters result in a value of δ = 0.55, or the composition of the synthesized compound as B4.55C. The high-resolution scans of boron binding energy reveal the existence of a B-C bond at 188.5 eV. Raman spectroscopy reveals the existence of a 386 cm-1 vibrational mode representative of C-B-B linear chain formation due to excess boron in the lattice. The measured Vickers microhardness at a load of 200 gf shows a high hardness value of 33.8 ± 2.3 GPa. Thermal gravimetric studies on B4.55C were conducted at a temperature of 1300 °C in a compressed dry air environment, and its behavior is compared to other high-temperature ceramic materials such as high-entropy transition metal boride. The high neutron absorption cross section, high melting point, high mechanical strength, and thermal oxidation resistance make this material ideal for applications in extreme environments.

Phase evolution and oxidation resistance of Si3N4/HfB2/HfBxCyN1–x–y ceramic nanocomposites prepared from tailored preceramic polymers

Single-source-precursor derived ceramics exhibit advantages for the preparation of Si-based ceramics with controllable phase composition and adjustable functional/mechanical properties, which has significant potential for (ultra)high temperature ceramic materials. Within the present work, a series of hafnium/boron-containing Si3N4-based ceramics (SiHfBCN) are prepared upon pyrolysis/annealing of the corresponding single-source-precursors in N2 atmosphere at different temperatures ranging from 1000 °C to 1700 °C. The high-temperature (micro)structural evolution with respect to the annealing temperatures and boron concentration was studied using X-ray powder diffraction, Raman spectroscopy, and transmission electron microscopy. The results show that the amorphous SiHfBCN ceramics convert upon crystallization into ceramic nanocomposites consisting of a α-Si3N4 matrix with embedded Si, HfB2, and HfBxCyN1–x–y. The formation and stability of HfBxCyN1–x–y solid solution were discussed in detail. Finally, the oxidation resistance of the obtained α-Si3N4/HfB2/HfBxCyN1–x–y ceramic nanocomposites was investigated by thermal gravimetric analysis in air.

Traditional vs. Automated Computer Image Analysis-A Comparative Assessment of Use for Analysis of Digital SEM Images of High-Temperature Ceramic Material.

Image analysis is a powerful tool that can be applied in scientific research, industry, and everyday life, but still, there is more room to use it in materials science. The interdisciplinary cooperation between materials scientists and computer scientists can unlock the potential of digital image analysis. Traditional image analysis used in materials science, manual or computer-aided, permits for the quantitative assessment of the coexisting components at the cross-sections, based on stereological law. However, currently used cutting-edge tools for computer image analysis can greatly speed up the process of microstructure analysis, e.g., via simultaneous extraction of quantitative data of all phases in an SEM image. The dedicated digital image processing software Aphelion was applied to develop an algorithm for the automated image analysis of multi-phase high-temperature ceramic material. The algorithm recognizes each phase and simultaneously calculates its quantity. In this work, we compare the traditional stereology-based methods of image analysis (linear and planimetry) to the automated method using a developed algorithm. The analysis was performed on a digital SEM microstructural image of high-temperature ceramic material from the Cu-Al-Fe-O system, containing four different phase components. The results show the good agreement of data obtained by classical stereology-based methods and the developed automated method. This presents an opportunity for the fast extraction of both qualitative and quantitative from the SEM images.

High-temperature deformation characteristics of 3D printing of nano-ceramic materials

In order to improve the application effect of three-dimensional printing of nano ceramic materials, the high-temperature deformation characteristics of three-dimensional printing of nano ceramic materials were studied. First, the main raw materials and experimental instruments for preparing nano ceramic materials were selected. Then, high-temperature nano ceramic materials were prepared by using 8%, 12%, and 15% polyester modified silicone resins respectively; And put it into the storage box of the direct writing 3D printer to print the 3D ceramic sample with the 3D printer. At last, the high temperature deformation characteristics under different high temperature environments are analysed. The results show that the adhesive force and salt spray resistance of 12% polyester modified silicone resin 3D ceramic specimens are good, and the bending strength of 12% polyester modified silicone resin 3D ceramic specimen is high, its structural stability is good, and the deformation value is small under the same high temperature environment.

Development, and characterisation of ultra-high-temperature ceramics composite (UHTC)

ABSTRACT Ultra high-temperature ceramic (UHTC) composite materials are physically and chemically stable at high temperatures (more than 2000°C) and in reactive environments. Generally, the family group of diboride, dicarbide, and dinitride are used as ultra-high temperature ceramic due to their high thermal conductivity and high melting point. The main aim of this paper is the development of zirconium diboride (ZrB2)-based UHTC and characterisation of their density, hardness, porosity, and work considered, three powder constituents B4C (35%), ZrB2 (55%), and Cr (10%) of particle size 30 μm, 15 μm, and 4 μm, respectively, the conventional sintering and spark plasma sintering technique is used for the development of composite. The results revealed that the relative density of conventionally sintered composite at 1600°C and 1700°C are 72% and 80%, respectively, and spark plasma sintered composite at 1900°C is 99.99%. The bulk density and apparent porosity of SPS composite at 1900°C are 4.73 g/cm3 and 4%, respectively. Similarly, bulk density and apparent porosity of conventionally sintered composite, at 1600°C are 2.49 g/cm3 and 30%, respectively, and at 1700°C is 2.89 g/cm3 and 27%, respectively. Furthermore, the hardness of the SPS composite at 1900°C is 2830 HV, while the hardness of conventionally sintered composite at 1700°C and 1800°C were 280 HV and 520 HV, respectively. Additionally, scanning electron microscopy was performed to observe the bonding and porosity in the microstructure of the UHTC.

Solution combustion synthesized micron sized yttrium aluminum garnet (Y3Al5O12) powder: A promising feedstock source for plasma spraying

Yttrium aluminum garnet (YAG) is a well-known high-temperature ceramic material that is used in a plethora of applications such as solid-state laser materials, cathode-ray tubes, field emission displays, scintillators, phosphors, electro-luminescent devices, etc. In recent years, plasma-sprayed yttrium aluminum garnet (YAG) has been explored as an alternative ceramic topcoat for thermal barrier coatings (TBCs) as it is known to prevent the oxidation of the bond coat. Also, it possesses high resistance to calcium magnesium aluminosilicate (CMAS) attack compared to conventional yttria-stabilized zirconia (YSZ) TBC topcoat material. In the current investigation, an attempt is made to fabricate plasma-sprayed YAG coating. The flowable powders required for plasma spraying are synthesized by the versatile solution combustion method after optimizing the process with two different fuels. The powders synthesized using hexamine fuel possess blocky angular-shaped particles and very good flowability. The flowability of the powders is correlated to the heat of combustion, adiabatic flame temperature and shape of the particles. The YAG powder synthesized from hexamine fuel is used for plasma spray application as the process results in higher yield and better flowability. The influence of different plasma spray powers (20, 30 and 40 kW) on the phase purity and crystallinity of the YAG coatings is studied using X-ray diffractometry. The influence of three different plasma powers on the microhardness and microstructure of the coatings is explored. The YAG coating plasma-sprayed at 30 kW is relatively a dense coating and exhibits a higher microhardness value of 1342 ± 9 HV at a load of 100 mN. The CMAS resistance of the YAG coatings is also reported.

Metallization, Material Selection, and Bonding of Interconnections for Novel LTCC and HTCC Power Modules.

Ceramic baseplates are important elements in the power modules of electric drives. This paper presents low-temperature cofired ceramic (LTCC) and high-temperature cofired ceramic (HTCC) materials for the fabrication of three-dimensional power modules. The silver-based metallization and power module assembly are presented, together with aluminum-based power wire bonding and an industrial procedure to achieve high solderability and bondability. The results of the bond tests using different metallization materials, especially cost-effective ones, are presented, together with the assembly of the power modules. The best results were achieved with Ag metallization and 380 µm Al wire and with Ag–Pd metallization and 25 µm Al wire, both on an LTCC base. The paper concludes with a dual-pulse electrical test of the power modules, which proves the quality of metallization, the type of material selected, and the correctness of the wire bonding and assembly.

Study of the heat capacity of VZhM4 nickel superalloy using differential scanning calorimetry, adiabatic and mixing calorimetry

An increase in the operating temperatures of assemblies and parts of modern aircraft is a key task for the aviation industry which entails developing of new materials that meet the increased requirements for their operational characteristics. A high level of the accuracy and reliability of the determined properties is one of the most important factors in designing high-temperature metal, ceramic and heat-shielding materials. The features of a particular measurement procedure, as well as their hardware design, do not always ensure the specified accuracy of experiments over the entire temperature range. We present the results of studying the heat capacity of VZhM4 nickel superalloy in the temperature range 100 – 1360° C by the methods of differential scanning calorimetry (DSC), adiabatic and mixing calorimetry. The data of the DSC analysis of the alloy, the temperatures of phase transformations and temperature dependences of the specific heat of the material are analyzed along with the assessment of their accuracy at different temperature intervals. A comparative analysis of the studied measurement procedures complements the research. The results obtained can be used in the development of new materials and in the study of the specific heat capacity of metal products in a wide temperature range.

Petrographic Analysis of Ancient High-Temperature Ceramic Glazes and Inorganic Restoration Materials

ABSTRACT The application of scientific and technological studies prior to the repair of historic and ancient ceramics can provide a more complete understanding of glazes to aid the conservator's decision-making process before undertaking the conservation of ceramics. There are two categories of Chinese glaze morphology for general high-temperature single-color glazes, calcium glazes (smooth glazes), and calcium alkali glazes (glazes containing more bubbles or crystals and multiple glazes). High-temperature colored glazes can be divided into four types: on-glazed, in-glazed, diffused, and under-glazed pigments. The subdivision of high-temperature glaze types has significance as a guiding factor in the repair of historic and ancient ceramic glazes. Optical coherence tomography (OCT) is discussed as a non-invasive way to understand glaze structure and as a tool to aid the conservator in the treatment of ceramics. Moreover, a silica sol-acrylic composite coating was studied as a possible material to use in the replication of ceramic glazes on areas of restoration. A small amount of acrylic resin can improve the reversibility of the synthetic coating. On the macro level, this coating exhibits natural glaze bubbles and craquelure similar to historic and ancient ceramics; in addition, on the micro level, it can imitate the clean calcium glaze and crystallization calcium alkali glaze of such ceramics. The silicon oxide content in this glaze-like material is found to be similar to that of historic and ancient ceramics.

Synthesis and characterizations of (Mg, Co, Ni, Cu, Zn)O high-entropy oxides

High-temperature structural ceramic materials require stability in terms of thermal and mechanical properties. High entropy oxides (HEOs) are among the emerging novel family of advanced ceramic materials with peculiar functional properties. However, their thermal stabilities and mechanical properties are not well investigated. In this work, HEO systems were synthesized from binary oxides of MgO, CoO, NiO, CuO, and ZnO using solid-state reaction method at high temperature, after obtaining the individual oxides through co-precipitation methods. The phase purity of as-synthesized and sintered samples was characterized using X-ray powder diffraction, while the microstructural investigation was performed using Scanning electron microscopy. Mechanical property of the sintered samples at different sintering times and temperatures was investigated and the sample sintered at a sintering temperature of 1200 °C for 15 h sintering time showed a maximum Vickers hardness of about 16 GPa. This result is comparable with some of the hard ceramic materials, and therefore the materials could be a potential candidate for structural applications.

High-pressure high-temperature synthesis and thermal equation of state of high-entropy transition metal boride

A high-entropy transition metal boride (Hf0.2 Ti0.2 Zr0.2 Ta0.2 Mo0.2)B2 sample was synthesized under high-pressure and high-temperature starting from ball-milled oxide precursors (HfO2, TiO2, ZrO2, Ta2O5, and MoO3) mixed with graphite and boron-carbide. Experiments were conducted in a large-volume Paris–Edinburgh press combined with in situ energy dispersive x-ray diffraction. The hexagonal AlB2 phase with an ambient pressure volume V0 = 27.93 ± 0.03 Å3 was synthesized at a pressure of 0.9 GPa and temperatures above 1373 K. High-pressure high-temperature studies on the synthesized high-entropy transition metal boride sample were performed up to 7.6 GPa and 1873 K. The thermal equation of state fitted to the experimental data resulted in an ambient pressure bulk-modulus K0 = 344 ± 39 GPa, dK/dT = −0.108 ± 0.027 GPa/K, and a temperature dependent volumetric thermal expansion coefficient α = α0 + α1T + α2 T−2. The thermal stability combined with a high bulk-modulus establishes this high-entropy transition metal boride as an ultrahard high-temperature ceramic material.

High-temperature heat-shielding, ceramic and ceramic-metal composite materials for new-generation aviation equipment

This paper describes achievements of the All-Russian Scientific Research Institute of Aviation Materials in the field of creating high-temperature heat-shielding, ceramic and metal-ceramic composite materials. The advantages and prospects of applying the developed materials in the manufacturing of structural elements of aircraft and friction joints are discussed. The synthesis features and basic properties of metal-ceramic composite materials based on light alloys, refractory metal matrices, ceramic composite materials for use in heavily loaded structural elements of modern aircraft are presented. The main achievements in the field of heat-shielding materials based on refractory oxide fibres are presented, along with their properties and application in new-generation aircrafts.

Research Progress of Magnesium Stabilized Aluminum Titanate and New Application of It in Pigment

Aluminum titanate has been widely used in low expansion applications and its thermal stability has been a hot topic. The stability of aluminium titanate research for improving product quality, and expanding its application field is of great significance. Aluminum titanate as glass melt erosion resistance and high temperature resistant, can be applied to high temperature pigment base. The medium temperature stability of aluminum titanate can be improved by ion doping, and magnesium stability of aluminum titanate has been widely studied. Therefore aluminium titanate is expected to become an ideal high temperature ceramic base material. In this paper, the preparation technology of magnesium-stabilized aluminum titanate powder was reviewed, and the preparation of magnesium-stabilized aluminum titanate powder by non-hydrolyzed sol-gel was mainly introduced.

Graphene and Carbone nanotubes reinforced ceramic nanocomposite TiO2-MgO: Experimental and numerical study

Ultra High Temperature Ceramic (UHTC) materials have attracted great interest for aerospace applications of hypersonic vehicles. They are subject to high aerodynamic forces and extreme heat fluxes where the surface temperature exceeds 2400 °C. The present work is first part of an experimental and numerical study of a new nanocomposite based on a ceramic matrix TiO2/MgO reinforced by Graphene Nano Platelets (GNP) or Carbone nanotubes (CNT). In the experimental part, the nanocomposite TiO2/MgO was elaborated by solid state mixing solutions, and the graphene oxides GO prepared by Hummers’s modified method, the obtained GO was reduced by Acid Ascorbic AA to achieved reduced graphene oxide rGO. On the other hand, the numerical part had been modelling two microstructures; the first is a ceramic composite reinforced by GNP, and the second is the same ceramic reinforced by CNT. Mori-Tanaka model is used as homogenization tool, with the multiscale representative volume element RVE approach. The goal of this work is to improve the stiffness and fracture toughness mechanisms by using nano particles. Wherein, the micromechanics models predict the mechanical performance of nanocomposites reinforced by aligned nano inclusion. The finite element model of composite is based on a Python code.

Analysis of a micro pressure-sensor employing SiC-AlN-SiC structure

ABSTRACT In this research paper, we design a touch mode capacitive micro pressure-sensor with circular stepped-cavity and SiC-AlN-SiC material structure, which can be more precisely measured pressure in a high-temperature environment. Using the finite element analysis method (based on ANSYS software), we found that the sensitivity of the sensor reached 3.5 pF/MPa, up almost one-third from traditional single-cavity structure in the long linear working range as 0.9–1.4 MPa. Moreover, the research to thermal behaviours of the sensor is shown that high temperature has affected the diaphragm deformation and the von Mises stress of the sensor due to thermal buckling. But the thermal deformation did not change the intrinsic characteristics of this sensor. Consequently, the sensor packaging with high-temperature ceramic material is endured the higher temperature to be applied in a harsh environment.