Journal articles: 'Ceramic materials - Electric properties'

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Sachidhananda, T. G., and V. Adake Chandrashekhar. "Electric Discharge Machining of Conducting Ceramics - A Review." Materials Science Forum 1019 (January 2021): 121–28. http://dx.doi.org/10.4028/www.scientific.net/msf.1019.121.

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Electrical Discharge machining (EDM) is a nonconventional machining technique, which has been widely used to produce dies and mold. Harder Materials can be machined into complex shapes as long as they conduct electricity. Recent advances in the technologies brought the development of new engineering materials, which are hard to machine with traditional machining processes. Being one of these materials, ceramics possess some unique properties like piezoelectricity and tribological properties which are not found in metal and polymers. EDM is capable of machining these ceramics, given these materials have an adequately high electrical conductivity. Preparing conducting ceramics is pre-requisite for incorporating ceramics in EDM. Different techniques such as compaction, tape casting, extrusion, injection molding and slip casting are used form green ceramic body. These green bodies are subsequently sintered to obtain ceramic parts. Adding conducting elements in the ceramics while processing results in conducting ceramics. These additions increase hardness but fracture toughness of body is compromised. Ceramic parts can also be machined by using assisting electrode and pyrolytic carbon technique. This paper discusses the various methods of shaping conducting ceramics and its machining characteristics for EDM application

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Tang, H., Y. J. Feng, Z. Xu, C. H. Zhang, and J. Q. Gao. "Effect of Nb doping on microstructure and electric properties of lead zirconate stannum titanate antiferroelectric ceramics." Journal of Materials Research 24, no. 5 (May 2009): 1642–45. http://dx.doi.org/10.1557/jmr.2009.0202.

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The aim of this work is to study the effect of Nb element doping on the microstructure and electrical properties of lead zirconate stannum titanate (PZST) ceramic and to improve phase transition properties of PZST. Nb-doped Pb(Zr,Sn,Ti)O3 ceramic samples were prepared by the conventional mixed oxide method. Phase transitions induced by temperature, pressure, and electric field were measured with electric dielectric permittivity, hydrostatic pressure, and hysteresis. The microstructure of the samples was observed by electron scanning microscope to discuss the effect of Nb doping on PZST ceramics. The experiment results indicated that the remnant polarization (Pr), dielectric constant, phase transition, and microstructure were strongly dependent on Nb doping content.

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Suastiyanti, Dwita, Yuli Nurul Maulida, and Merlin Wijaya. "Improving of Electric Voltage Response Based on Improving of Electrical Properties for Multiferroic Material of BiFeO₃-BaTiO₃ System." Key Engineering Materials 867 (October 2020): 54–61. http://dx.doi.org/10.4028/www.scientific.net/kem.867.54.

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Synthesis of nanomultiferroic material with the active content of bismuth ferrite (BiFeO3) and barium titanate (BaTiO3) was carried out. It is considering that it was difficult to obtain single phase of BiFeO3 as a base material for multiferroic materials. It is expected that the addition of BaTiO3 on ceramic alloys consist of BiFeO3 and BaTiO3 can improve the electrical properties of the ceramics and finally it improves the multiferroic properties of the material. Multiferroic properties could be seen from the appearance of an electric voltage response if the material is given the effect of an external magnetic field. The synthesis uses the sol gel method which is a good method of producing nanosized material. Synthesis of nanomultiferroic ceramic materials is carried out by varying the weight ratio of BaTiO3 and BiFeO3 of 2: 1, calcination temperature of 350°C for 4 hours and sintering temperatures with variations of 700°C; 750°C and 800°C for 2; 4; and 6 hours. Characterization was carried out using X Ray Diffraction (XRD) to confirm phase formation. The electrical properties test which produces a hysterical loop is carried out to determine the value of remanent, coercivity and electric polarization saturation. Particle size measurements were carried out using the Beckman Coulter DelsaTM nanoinstrument. The multiferroic phenomena is known from the appearance of an electric voltage response if there is an effect of an external magnetic field on the material. The smallest particle size was obtained on ceramic powder which experienced sintered of 750°C. The best values of remanent, coercivity and electric polarization were obtained on ceramics which were sintered at temperatures of 750°C for 6 hours. This is linear with the highest value of electrical voltage arising as a result of the effect of the external magnetic field given to the ceramic material. Material that has a large electrical voltage response shows good multiferroic properties.

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Deng, Yunfeng, Junjun Wang, Chunxiao Zhang, Hui Ma, Chungeng Bai, Danqing Liu, Fengmin Wu, and Bin Yang. "Structural and Electric Properties of MnO2-Doped KNN-LT Lead-Free Piezoelectric Ceramics." Crystals 10, no. 8 (August 15, 2020): 705. http://dx.doi.org/10.3390/cryst10080705.

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Structural, ferroelectric, dielectric, and piezoelectric properties of K0.5Na0.5NbO3-LiTaO3-xmol%MnO2 lead-free piezoelectric ceramics with 0.0 ≤ x ≤ 0.3 were studied. The ceramic samples were synthesized through the conventional solid-state reaction method. The MnO2 addition can reduce the sintering temperature of KNLNT ceramics. Compared with undoped KNLNT ceramic, the piezoelectric measurements showed that piezoelectric properties of K0.5Na0.5NbO3-LiTaO3-xMnO2 were improved (d33 = 251 pC/N) when x = 0.1. In addition, KNLNT-xMnO2 ceramics have larger Pr(20.59~21.97 μC/cm2) and smaller Ec(10.77~6.95 kV/cm), which indicates MnO2 has excellent softening property, which improves the ferroelectric properties of KNLNT ceramics This work adds relevant information regarding of potassium sodium niobate K0.5Na0.5NbO3 (KNN) when doped Li, Ta, Mn at the B-site.

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Savvova, O. V., G. K. Voronov, S. A. Ryabinin, E. Yu Fedorenko, and V. D. Timofeev. "Alumina silicate glass-ceramic materials for electrical purposes." Scientific research on refractories and technical ceramics 120 (December 30, 2020): 174–85. http://dx.doi.org/10.35857/2663-3566.120.17.

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The prospects for use of glass-ceramic materials as electrical products were analyzed. The priority of a self-organized macro- and nanostructure formation of the glass-ceramic materials under conditions of low-temperature heat treatment to ensure their high physical and chemical properties was shown. The choice of an alumina silicate system of materials for obtaining high-strength glass-ceramic materials with improved electrical properties was substantiated, taking into account the aspects of energy saving. The technological modes of cooking, forming and heat treatment of glass-ceramic materials were determined. Resistance, dielectric constant and dielectric loss tangent at 106 Hz were measured using an E6-13A teraometer on a trielectrode system at a temperature of +29 °C and a DE-5000 RLC meter. Electric strength (Em) and cold crushing strength were determined according to GOST 24409-80. Tensile strength according to GOST 32281.1-2013 (EN 1288-1: 2000). The decisive influence on the electrical properties of glass-ceramic materials the crystalline phases of α-cordierite, β-spodumene or lithium disilicate, as well as the residual glass phase composition has been established. The structure influence of the alumina silicate glass-ceramic materials on the provision of their electrical (tgδ∙104 = 70 ÷ 80; ε = 8.0 ÷ 9.3 (at f = 106 Hz); lg ρv = 12.9 ÷ 15.0 (ρv, Ohm·cm at Т = 20 °C) and mechanical (K1C = 3.15 ÷ 4.3 МPа∙м1/2; σ comp = 630 ÷ 700 МPа, σbend = 300 ÷ 350 МPа; KCU = 4.8 ÷ 5.9 kJ/m2) properties. It was found that, the defining condition for the developed glass-ceramic materials use as insulating materials under repeated exposure to high-temperature operations is their high breakdown strength Em = 37 ÷ 42 MV/m and thermal shock resistance due to low TCLE (α∙107 = 21.5 ÷ 31.8 deg-1). The influence of phase composition and structure of the alumina silicate glass-ceramic materials on their electrical and mechanical properties was analyzed. A comparative assessment of the known ceramic and glass-ceramic materials for electrical purposes has made it possible to establish the feasibility of using the developed materials as substrates in the design of a hybrid integrated circuit, vacuum-tight shell and capacitor dielectrics.

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Zhang, Jing, Pinghua Pan, Ping Jiang, Jie Qin, and Jiansong Hu. "Electric degradation in PZT piezoelectric ceramics under a DC bias." Science and Engineering of Composite Materials 27, no. 1 (December 31, 2020): 464–68. http://dx.doi.org/10.1515/secm-2020-0049.

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AbstractIn order to accurately evaluate the service life and failure mechanism of the PZT piezoelectric ceramics, the electric degradation process of the PZT ceramics with and sans doping under a DC voltage of 380V, in a surrounding environment of 90∘C and 85% RH has been investigated using a self-made device. The experimental results show that the degradation rate of the pure PZT ceramic is lower than that of ceramics with doping in the same condition. Furthermore, the electrical properties of the ceramics tend to decrease during the electric degradation. The doping increases the defects of ceramics, resulting in that the silver ion transfer from the anode to the cathode under the continuous DC bias, which can further form a metal band, increasing the conductivity, but deteriorating the service life.

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Molak, A., and J. Suchanicz. "Electric properties of ceramic Na0.5Bi0.5TiO3under axial pressure." Ferroelectrics 189, no. 1 (December 1996): 53–59. http://dx.doi.org/10.1080/00150199608213404.

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Albutt, Naphat, Suejit Pechprasarn, and Thanapong Sareein. "Influence of Currents and Electric Fields in YNMO Ceramics." Applied Mechanics and Materials 866 (June 2017): 256–58. http://dx.doi.org/10.4028/www.scientific.net/amm.866.256.

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Development of ceramic materials is critical for new and improved electronic applications. Herein, the J-E response of Y2NiMnO6 (YNMO) ceramics composited by a solid state reaction method was investigated. Sintering temperature and time were found to have significant influence on the ceramics electrical properties. In particular, higher temperatures and longer sintering times resulted in more favourable dielectric properties of the YNMO ceramics. A current of 40 mA/cm2 at 20,000 mV/cm was obtained by sintering at 1300 °C for 12 hours, whereas a current of 9 mA/cm2 at 4000 mV/cm can be achieved by sintering at 1400 °C for 24 hours. These results will be useful for identifying applications for YNMO ceramics. The electrical properties of the YNMO ceramics can be tuned for different electronic components such as dry batteries and capacitors.

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Bochenek, Dariusz, Joanna A. Bartkowska, Lucjan Kozielski, and Izabela Szafraniak-Wiza. "Mechanochemical Activation and Spark Plasma Sintering of the Lead-Free Ba(Fe1/2Nb1/2)O3 Ceramics." Materials 14, no. 9 (April 27, 2021): 2254. http://dx.doi.org/10.3390/ma14092254.

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This paper investigates the impact of the technological process (Mechanochemical Activation (MA) of the powder in combination with the Spark Plasma Sintering (SPS) method) on the final properties of lead-free Ba(Fe1/2Nb1/2)O3 (BFN) ceramic materials. The BFN powders were obtained for different MA duration times (x from 10 to 100 h). The mechanically activated BFN powders were used in the technological process of the BFN ceramics by the SPS method. The measurements of the BFNxMA ceramic samples included the following analysis: Scanning Electron Microscopy (SEM), Energy Dispersive Spectrometry (EDS), DC electrical conductivity, and dielectric properties. X-ray diffractions (XRD) tests showed the appearance of the perovskite phase of BFN powders after 10 h of milling time. The longer milling time (up 20 h) causes the amount of the perovskite phase to gradually increase, and the diffraction peaks are more clearly visible. Short high energy milling times favor a large heterogeneity of the grain shape and size. Increasing the MA milling time to 40 h significantly improves the microstructure of BFN ceramics sintered in the SPS technology. The microstructure becomes fine-grained with clearly visible grain boundaries and higher grain size uniformity. Temperature measurements of the BFN ceramics show a number of interesting dielectric properties, i.e., high values of electric permittivity, relaxation properties with a diffusion phase transition, as well as negative values of dielectric properties occurring at high temperatures. The high electric permittivity values predestines the BFNxMA materials for energy storage applications e.g., high energy density batteries, while the negative values of dielectric properties can be used for shield elements against the electromagnetic radiation.

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Mitić, Vojislav V., Zoran S. Nikolić, Ivona Mitrović, Branka Jordović, and Vladimir Brankov. "THE APPLICATION OF STEREOLOGY METHOD FOR ESTIMATING THE NUMBER OF 3D BaTiO3 – CERAMIC GRAINS CONTACT SURFACES." Image Analysis & Stereology 20, no. 3 (May 3, 2011): 231. http://dx.doi.org/10.5566/ias.v20.p231-237.

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Methods of stereological study are of great importance for structural research of electronic ceramic materials including BaTiO3-ceramic materials. The broad application of ceramics, based on barium-titanate, in advanced electronics nowadays demands a constant research of its structure, that through the correlation structureproperties, a fundamental in the basic materials properties prognosis triad (technology-structure-properties), leads to further prognosis and properties design of these ceramics. Microstructure properties of BaTiO3- ceramic material, expressed in grains' boundary contact, are of basic importance for electric properties of this material, particularly the capacity. In this paper, a significant step towards establishing control under capacitive properties of BaTiO3-ceramics is being done by estimating the number of grains contact surfaces. Defining an efficient stereology method for estimating the number of BaTiO3-ceramic grains contact surfaces, we have started from a mathematical model of mutual grains distribution in the prescribed volume of BaTiO3-ceramic sample. Since the real microstructure morphology of BaTiO3-ceramics is in some way disordered, spherical shaped grains, using computer-modelling methods, are approximated by polyhedra with a great number of small convex polygons. By dividing the volume of BaTiO3-ceramic sample with the definite number of parallel planes, according to a given pace, into the intersection plane a certain number of grains contact surfaces are identified. According to quantitative estimation of 2D stereological parameters the modelled 3D internal microstructure is obtained. Experiments were made by using the scanning electronic microscopy (SEM) method with the ceramic samples prepared under pressing pressures up to 150 MPa and sintering temperature up to 1370°C while the obtained microphotographs were used as a base of confirming the validity of presented stereology method. This paper, by applying computer stereology method for estimating the number of grains contact surfaces, makes possible a further insight into the microstructure of BaTiO3-ceramics with the final aim to design new properties of electronic materials based on barium - titanate ceramics.

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Lee, Sang Heon. "Superconducting Properties of YBaCuO Bulk Superconductors." Journal of Nanoelectronics and Optoelectronics 14, no. 12 (December 1, 2019): 1755–58. http://dx.doi.org/10.1166/jno.2019.2672.

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The use of a high-temperature superconductor to manufacture products for commercialization requires a superconductor with a flexible function designed to meet the characteristics of each product. Appropriate mechanical properties need to be maintained to overcome the Lorenz force generated under high magnetic fields. Several studies focused on the improvement of superconductivity and the development of processing technology. However, high temperature superconductivity wires are not intended for large-scale applications at liquid nitrogen temperature (77 K). Recently, ceramic superconductors have been fabricated into bulk and thin films or wire rods for electric power applications; however, ceramics are hard to deform due to increased hardness, which is one of the biggest limitations of a superconductor, and a major obstacle to industrial applications. To overcome these limitations, a synthetic method for superconductivity to reduce the hardness of ceramic superconductor and prevent its degradation was proposed for applications such as superconductivity power cables and wires in energy and electric machines using superconductors.

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Wang, Chun Huy. "Grain Growth and Electric Properties of Lead-Free BaTiO₃ Ceramics." Key Engineering Materials 368-372 (February 2008): 1919–22. http://dx.doi.org/10.4028/www.scientific.net/kem.368-372.1919.

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Many lead-free materials, such as Bi-based compounds, BaTiO3 or alkaline niobate compound, have been intensively studied. The microstructure and characteristics of BaTiO3 ceramics are significantly influenced by addition of 4PbO-B2O3. Under low sintering temperatures, the grain growth of BaTiO3 ceramic is enhanced by capillary action, rearrangement and solution-reprecipitation of the liquid phase. At high sintering temperatures, exaggerated grain growth of BaTiO3 ceramic is restrained by the presence of a liquid phase. The theory of grain growth in the presence of a liquid phase is examined in terms of the equation Rn = k× t. The grain growth kinetic exponent, n, has an inverse relationship with the rate of grain growth. With suitable amounts of glass frit and an optimized sintering temperature, the density is enhanced and the values of the dielectric and piezoelectric properties are improved.

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Garcia-Sanchez, Angela M., Bernardino Machado-Moreira, Mário Freire, Ricardo Santos, Sílvia Monteiro, Diamantino Dias, Orquídia Neves, Amélia Dionísio, and Ana Z. Miller. "Characterization of Microbial Communities Associated with Ceramic Raw Materials as Potential Contributors for the Improvement of Ceramic Rheological Properties." Minerals 9, no. 5 (May 23, 2019): 316. http://dx.doi.org/10.3390/min9050316.

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Technical ceramics are being widely employed in the electric power, medical and engineering industries because of their thermal and mechanical properties, as well as their high resistance qualities. The manufacture of technical ceramic components involves complex processes, including milling and stirring of raw materials in aqueous solutions, spray drying and dry pressing. In general, the spray-dried powders exhibit an important degree of variability in their performance when subjected to dry-pressing, which affects the efficiency of the manufacturing process. Commercial additives, such as deflocculants, biocides, antifoam agents, binders, lubricants and plasticizers are thus applied to ceramic slips. Several bacterial and fungal species naturally occurring in ceramic raw materials, such as Sphingomonas, Aspergillus and Aureobasidium, are known to produce exopolysaccharides. These extracellular polymeric substances (EPS) may confer unique and potentially interesting properties on ceramic slips, including viscosity control, gelation, and flocculation. In this study, the microbial communities present in clay raw materials were identified by both culture methods and DNA-based analyses to select potential EPS producers based on the scientific literature for further assays based on the use of EPS for enhancing the performance of technical ceramics. Potential exopolysaccharide producers were identified in all samples, such as Sphingomonas sp., Pseudomonas xanthomarina, P. stutzeri, P. koreensis, Acinetobacter lwoffi, Bacillus altitudinis and Micrococcus luteus, among bacteria. Five fungi (Penicillium citrinum, Aspergillus niger, Fusarium oxysporum, Acremonium persicinum and Rhodotorula mucilaginosa) were also identified as potential EPS producers.

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Guo, Chen Jie, and Chang Song Zhang. "Research on Properties of PZT Piezoelectric Ceramics by Finite Element Softeware ADINA." Applied Mechanics and Materials 130-134 (October 2011): 3233–36. http://dx.doi.org/10.4028/www.scientific.net/amm.130-134.3233.

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In this paper, the finite element model of piezoelectric ceramics in line with the experiment results was established according to piezoelectric structure field and the coupling of the electric field, deformation of representative PZT piezoelectric ceramics under the voltage was analysed in using finite element analysis software ADINA according to establishing geometric model, defining boundary conditions and materials, Coupling calculation. Consistency between simulation results and experimental results is improved and lay the foundation for the realization of the piezoelectric ceramic shapes and vibration control.

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Hotza, Dachamir, and Antonio Pedro Novaes de Oliveira. "New Silicate Glass-Ceramic Materials and Composites." Advances in Science and Technology 68 (October 2010): 1–12. http://dx.doi.org/10.4028/www.scientific.net/ast.68.1.

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New silicate glass-ceramic compositions have been investigated due to their interesting chemical, mechanical, thermal, and electrical properties. LZSA glass-ceramics based on -spodumene (Li2O•Al2O3•4-10SiO2) and zircon (ZrSiO4) crystalline phases have shown good chemical resistance, high bending strength as well as high abrasion resistance, when compared with traditional ceramic materials, and coefficient of thermal expansion from 4.6 to 9.110-6 °C-1. These features basically depend on the nature, size and distribution of the formed crystals as well as on the residual glassy phase. The nature of the formed crystalline phases and consequently the final properties can be controlled by modifying the chemical composition of the parent glass and also by adequate selection of the heat-treatment parameters. The classical fabrication of glass-ceramic materials consists on the preparation of monolithic glass components followed by heat treatments for crystallisation. However, this technology requires high investments and can be justified only for large production. A viable alternative could be the production of glass-ceramics processed from glass powders and consolidated by sintering using the same equipments of traditional ceramic plants. This work reports the manufacturing and characterization of glass-ceramic materials and composites processed by pressing, injection moulding, extrusion, casting, replication, and rapid prototyping.

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Teo, Pao Ter, Siti Koriah Zakaria, Nurulakmal Mohd Sharif, Anasyida Abu Seman, Mustaffa Ali Azhar Taib, Julie Juliewatty Mohamed, Mahani Yusoff, et al. "Application of General Full Factorial Statistical Experimental Design’s Approach for the Development of Sustainable Clay-Based Ceramics Incorporated with Malaysia’s Electric Arc Furnace Steel Slag Waste." Crystals 11, no. 4 (April 19, 2021): 442. http://dx.doi.org/10.3390/cryst11040442.

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This study aims to optimize the composition (body formulation) and firing temperature of sustainable ceramic clay-based ceramics incorporated with electric arc furnace (EAF) steel slag waste using general full factorial design (GFFD). The optimization is necessary to minimize drawbacks of high iron oxide’s fluxing agent (originated from electric arc furnace, EAF steel slag waste), which led to severe surface defects and high closed porosity issue of the ceramics. Statistical analysis of GFFD including model adequacy checking, analysis of variance (ANOVA), interaction plots, regression model, contour plot and response optimizer were conducted in the study. The responses (final properties of ceramics) investigated were firing shrinkage, water absorption, apparent porosity, bulk density and modulus of rupture (MOR). Meanwhile, the factors employed in experimental parameters were weight percentage (wt.%) of EAF slag added and firing temperature. Upon statistical analysis, GFFD has deduced that wt.% amount of EAF slag added and firing temperatures are proven to significantly influence the final properties of the clay-based ceramic incorporated with EAF slag. The results of conducted statistical analysis were also highly significant and proven valid for the ceramics. Optimized properties (maximum MOR, minimum water absorption and apparent porosity) of the ceramic were attained at 50 wt.% of EAF slag added and firing temperature of 1180 °C.

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Nowakowski, Andrzej, Tadeusz Krzywda, and Piotr Putyra. "EDM processing of sintered ceramic materials using the SPS method." Mechanik 91, no. 3 (March 5, 2018): 240–43. http://dx.doi.org/10.17814/mechanik.2018.3.39.

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Presented are the analysis of physical and mechanical properties of the Al2O3, SiC and Si3N4 matrix ceramics with additives of good electrical conductivity phases and TiB2 matrix ceramics. The density, Young’s modulus, hardness HV1 and electrical conductivity of each material were investigated. Ceramic composite materials with the participation of the conductive phases have been produced using SPS (spark plasma sintering) method. Materials characterized by good electrical conductivity were shaped using EDM (electro discharge machining) method.

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Wang, Jing, Han Wang, He Jiang, Xiaohui Wang, Yuanhua Lin, and C. W. Nan. "Large Electric-Field Modulation of Magnetic Properties in Fe Films on BiScO3-PbTiO3Ceramics." Journal of Nanomaterials 2010 (2010): 1–6. http://dx.doi.org/10.1155/2010/142750.

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Based on the magneto-optical Kerr effect, we report the electric-field modulation of the magnetic properties inFe/BiScO3-PbTiO3(BSPT) film-on-ceramic substrate structure. The Fe films are directly grown on the fully-poled BSPT ceramic substrates by magnetron sputtering. An electric field applied parallel to the prepolarization direction of the piezoelectric BSPT can induce a reversible increase in the coercive fieldHcof about 30%, whereas an electric field antiparallel to the prepolarization direction can cause a persistent, tremendous decrease (as large as 97%) inHc, and a small reversal electric field can resume it back. The strain induced by the inverse piezoelectric effect is the primary mechanism behind. This large modulation of the coercive field by the electric field could inspire further exploration of electric-field-controlled magnetic switching in multiferroic heterostructures.

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Chen, Yu Fei, Yan Gai Liu, Xiao Wen Wu, Zhao Hui Huang, and Ming Hao Fang. "Microstructure, Mechanical Properties, and Electrical Resistivities of Mica Glass-Ceramics with Flake Phlogopite and Waste Glass." Key Engineering Materials 602-603 (March 2014): 640–43. http://dx.doi.org/10.4028/www.scientific.net/kem.602-603.640.

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Mica glass-ceramics can be applied in all kinds of electrical equipment, locomotive internal circuits in high-speed rail, ordinary electric locomotive and subway locomotive. In this study, mica glass-ceramics were prepared by sintering process using flake mica and waste glass as the main raw material with low cost. Different mica glass-ceramic samples were fabricated by changing the formula of raw materials, molding process and sintering temperature. X-ray diffraction, scanning electron microscopy, three-point bending test, and balanced-bridge technique were applied to investigate the phase, microstructure, mechanical and electrical resistivities of the samples, respectively. The results show that the optimum sintering temperature is 900 to 1000 °C holding for two hours, the desirable ratio is 70 wt% of mica powder while 30 wt% of glass powder. In that condition the sample could be less porosity, high flexural strength (63.3 MPa) and eligible electrical resistivity (0.4×1013 Ω·cm).

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León-Patiño, Carlos A., Deisy Ramirez-Vinasco, Ena A. Aguilar-Reyes, and Makoto Nanko. "Synthesis and Properties of Pulsed Electric Current Sintered AlN/Cu Composites." MRS Advances 3, no. 62 (2018): 3611–19. http://dx.doi.org/10.1557/adv.2018.671.

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ABSTRACTThis research shows the development of alternative Cu-based materials for applications where enhanced thermal properties are desired. Cu/AlN composites were fabricated from mixtures of pure Cu and copper plated AlN-Cu composite powders. The ceramic phase was added in amounts of 10, 20 and 30 vol.% and the mixtures sintered by pulsed electric current sintering process (PECS). The results showed that the AlN particles are homogeneously distributed in the copper matrix and that the true contacts between hard particles are reduced because of the deposited copper on their surfaces, improving the connectivity of the matrix phase and bonding at the metal-ceramic interface. The relative density of the Cu/AlN composites was major than 97% in all cases. Thermal conductivity of the composites was high and decreased with the ceramic content from 359 to 194 W/mK, for 10 and 30% AlN, respectively. The coefficient of thermal expansion followed a lineal behavior with temperature and is also reduced with the ceramic content.

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Lavrynenko, S., E. Gevorkyan, W. Kucharczyk, L. Chalko, and M. Rucki. "Cutting Capacity and Wear Resistance of Cr2O3-AlN Nanocomposite Ceramic Obtained by Field Activated Sintering Technique (Fast)." Advances in Materials Science 18, no. 3 (September 1, 2018): 15–21. http://dx.doi.org/10.1515/adms-2017-0037.

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AbstractChromium oxide ceramics may be considered as a new generation of ceramic materials for cutting tools with considerably improved high speed cutting performance. The present work is focused on the development of Cr2O3 nanocomposite materials fabricated with the Field Activated Sintering Technique (FAST). The main objective of the proposed work is to study the influence of electric field on the densification process during FAST sintering of the materials in the Cr2O3-AlN system with nanosize microstructure. Additional objectives are to characterize mechanical properties of the obtained Cr2O3 ceramics. The work aimed to develop composite materials based on Cr2O3-based nanoparticles for cutting, then to check their cutting properties and to work out the recommendations for their use for processing of various materials, accordingly.

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Liuyang, Han, Ponchel Freddy, Rémiens Denis, Lasri Tuami, Tiercelin Nicolas, Wang Genshui, and Pernod Philippe. "A comparison of converse magnetoelectric coupling effect of YIG film on FE and AFE ceramic substrates." Ferroelectrics 557, no. 1 (March 11, 2020): 1–8. http://dx.doi.org/10.1080/00150193.2020.1713349.

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The magnetoelectric properties of laminated heterostructures consisting of ferromagnetic yttrium iron garnet (YIG) films deposited on antiferroelectric (AFE) (Pb0.97La0.02)(Zr0.6Sn0.3Ti0.1)O3 (PLZST) and on ferroelectric (FE) 0.75Pb(Mg1/3Nb2/3)O3-0.25Pb(Zr0.48Ti0.52)O3 (PMN-PZT) ceramics are compared in this work. In particular, the Converse Magneto Electric (CME) coefficient is evaluated for these two types of structures. When the electric field is applied on an AFE ceramic, the CME coefficient peaks at the switching field and, without bias magnetic field, the maximum value is 11.6 × 10−8 s/m. In case of a FE ceramic, at the electric coercive field, the CME coefficient can reach 17 × 10−8 s/m at 0 Oe. Each structure has advantages and disadvantages depending on the applications.

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Xu, Z., and D. A. Payne. "Interphases and interfaces in BaTiO3-NaNbO3 ceramics." Proceedings, annual meeting, Electron Microscopy Society of America 44 (August 1986): 834–35. http://dx.doi.org/10.1017/s0424820100145510.

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The properties of polycrystalline ceramics are greatly influenced by the boundary conditions which exist within ceramic microstructures. This is especially so for dielectric materials, where discontinuities in periodicity and variations in chemical heterogeneity, perturb electric flux passage through ceramic microstructures. In this investigation, dielectric mixtures in the system BaTiO3-NaNbO3 were prepared by liquid-phase sintering methods. The purpose was to distribute a continuously connected minor phase (e.g., NaNbO3) within the boundary regions of BaTiO3-based ceramics. Characterization data are presented, from TEM and STEM analyses, for the grain-size dependence on niobate content; and for the spatial distribution of Nb from the interphase into the interfacial region.

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Chen, Yun, Huihua Ye, Xusheng Wang, Yanxia Li, and Xi Yao. "Mechanical and electric properties of ferroelectric Ba1-xCaxTiO3 ceramic." Ferroelectrics 558, no. 1 (April 3, 2020): 128–39. http://dx.doi.org/10.1080/00150193.2020.1735897.

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Smirnov, Konstantin L., E. G. Grigoryev, and E. V. Nefedova. "SiAlON-TiN Ceramic Composites by Electric Current Assisted Sintering." Materials Science Forum 946 (February 2019): 53–57. http://dx.doi.org/10.4028/www.scientific.net/msf.946.53.

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Electric current assisted sintering of β-Si5AlON7-TiN ceramic composites from raw materials prepared by combustion synthesis was investigated. A high level of relative density (92% and higher) was achieved by using of two types of electric current assisted sintering technique: high voltage electric discharge consolidation, as well as spark plasma sintering. While only spark plasma sintering, it may be considered as promising technique for obtaining ceramic composites and items with high level of strength properties.

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Tsurumi, T., Y. Yamamoto, H. Kakemoto, S. Wada, H. Chazono, and H. Kishi. "Dielectric properties of BaTiO3–BaZrO3 ceramics under a high electric field." Journal of Materials Research 17, no. 4 (April 2002): 755–59. http://dx.doi.org/10.1557/jmr.2002.0110.

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Multilayered ceramic capacitors (MLCCs) with BaTiO3–BaZrO3 (BTZ) dielectric layers were fabricated, and the dielectric permittivity of the BTZ layers with different thicknesses in MLCCs was measured. The dielectric permittivity of the BTZ ceramic disk was also measured under various ac electric fields. The variation in the dielectric behaviors with the thickness of BTZ layers in MLCCs was explained by the ac-field dependence of dielectric permittivity observed in the BTZ ceramic disk. The ac-field dependence of dielectric permittivity of BTZ was markedly observed below the temperature of a broad maximum in the dielectric permittivity versus temperature (є versus T) curve. It was found that the temperature of the broad maximum shifted to the low-temperature side and the peak shape became asymmetric with increasing ac field. These changes in the dielectric properties under high ac fields were explained by a model of relaxors with the concept of the formation of polar microregions (PMRs) and the freezing of fluctuating ipoles in PMRs.

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Fu, YaBo, HaoNan Chen, ZhiQiang Cao, and YanQiu Huo. "Effect of CeO2 Nanoparticles on Interface of Cu/Al2O3 Ceramic Clad Composites." Materials 13, no. 5 (March 9, 2020): 1240. http://dx.doi.org/10.3390/ma13051240.

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Cu/Al2O3 ceramic clad composites are widely used in electronic packaging and electrical contacts. However, the conductivity and strength of the interfacial layer are not fit for the demands. So CeO2 nanoparticles 24.3 nm in size, coated on Al2O3 ceramic, promote a novel CeO2–Cu2O–Cu system to improve the interfacial bonded strength. Results show that the atom content of O is increased to approximately 30% with the addition of CeO2 nanoparticles compared with the atom content without CeO2 in the interfacial layer of Cu/Al2O3 ceramic clad composites. CeO2 nanoparticles coated on the surface of Al2O3 ceramics can easily diffuse into the metallic Cu layer. CeO2 nanoparticles can accelerate to form the eutectic liquid of Cu2O–Cu as they have strong functions of storing and releasing O at an Ar pressure of 0.12 MPa. The addition of CeO2 nanoparticles is beneficial for promoting the bonded strength of the Cu/Al2O3 ceramic clad composites. The bonded strength of the interface coated with nanoparticles of CeO2 is increased to 20.8% compared with that without CeO2; moreover, the electric conductivity on the side of metallic Cu is 95% IACS. The study is of great significance for improving properties of Cu/Al2O3 ceramic clad composites.

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Zhao, Quanlu, Juntao Zhao, and Xiangfeng Tan. "Classification, preparation process and its equipment and applications of piezoelectric ceramic." Materials Physics and Chemistry 1, no. 1 (February 7, 2018): 20. http://dx.doi.org/10.18282/mpc.v1i1.560.

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The so-called piezoelectric ceramic is a piezoelectric polycrystal, a functional ceramic material capable of inter-converting mechanical energy and electric energy. It belongs to inorganic nonmetallic materials. So far, the most widely used piezoelectric ceramic materials have both good piezoelectricity and ferroelectricity through the substitution and doping in a wide range to adjust its properties to meet the diﬀerent needs of zirconium titanium lead (PZT) and its composite materials. Piezoelectric ceramic is also one of the prevailing piezoelectric materials, accounting for about 1/3 of the entire functional ceramic materials. It is mainly used for transducers, sensors, resonators and drives.

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Li, Quan Lu, Jing Wu, Yin Hong Zhang, Ran Liao, Hai Xia Cheng, and Qing Qing Yang. "The Effects of Superfine Powder and Sintering Technique upon Properties and Applications of some Piezoelectric Ceramics." Advanced Materials Research 749 (August 2013): 3–12. http://dx.doi.org/10.4028/www.scientific.net/amr.749.3.

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This paper briefly reports on the improved properties and bettered applications of some piezoelectric ceramics (i. e. S-PZT, etc.) of ferro/piezoelectric community by means of bettering their technological process links, especial superfine grinding of powder of raw materials, and sintering technique of piezoelectric ceramics in them. These piezoelectric ceramic materials have obtained the better effect in their newly and widely applied aspects, such as, acoustoelectric transducing; electrical to mechanical to electrical transducing; acoustooptic effect; electrooptic technique, and, piezoelectric ceramics for high voltage generators, ignition and detonation purposes, and some original applications (e.g., combining the electrorheological fluids) etc.. As far as appropriate measure of the improving sintering and other technique processes in present work is concerned, they also have reference value to electronic ceramics of having similar manufacturing technological process, such as capacitor ceramics, resistance ceramics, magnetic ceramics, and oxide ceramic superconducting materials, etc..

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Silvestre, J., N. Silvestre, and J. de Brito. "An Overview on the Improvement of Mechanical Properties of Ceramics Nanocomposites." Journal of Nanomaterials 2015 (2015): 1–13. http://dx.doi.org/10.1155/2015/106494.

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Due to their prominent properties (mechanical, stiffness, strength, thermal stability), ceramic composite materials (CMC) have been widely applied in automotive, industrial and aerospace engineering, as well as in biomedical and electronic devices. Because monolithic ceramics exhibit brittle behaviour and low electrical conductivity, CMCs have been greatly improved in the last decade. CMCs are produced from ceramic fibres embedded in a ceramic matrix, for which several ceramic materials (oxide or non-oxide) are used for the fibres and the matrix. Due to the large diversity of available fibres, the properties of CMCs can be adapted to achieve structural targets. They are especially valuable for structural components with demanding mechanical and thermal requirements. However, with the advent of nanoparticles in this century, the research interests in CMCs are now changing from classical reinforcement (e.g., microscale fibres) to new types of reinforcement at nanoscale. This review paper presents the current state of knowledge on processing and mechanical properties of a new generation of CMCs: Ceramics Nanocomposites (CNCs).

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kanzaoui, M. El, A. Hajjaji, A. Guenbour, and R. Boussen. "Development and study of mechanical behaviour reinforcing composites by waste BTP." MATEC Web of Conferences 149 (2018): 02012. http://dx.doi.org/10.1051/matecconf/201814902012.

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Composite materials are used in many industrial applications for their excellent mechanical and electric properties and their low density compared to metal structures. Most countries are extremely rich waste materials such as white ceramic breakages which represents a potential to be developed. Ceramic breakages have exceptional properties and could be effectively exploited in the manufacture of composite materials for a wide variety of applications. The composite materials reinforced by construction waste materials, such as ceramic breaks which offer significant benefits and gains in strength and stiffness properties (Young's modulus E : a material whose modulus Young is very high is said rigid).This article covers the benefits of breakages as ceramic filler used for reinforcement in composites, as well as improve the mechanical response of these structural elements (test compression).

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Ognev, Alexey, Alexander S. Samardak, Vladimir Pechnikov, and Evgeniy Papynov. "SPS Temperature Influence on the Composition, Structure and Magnetic Properties of Hematite Ceramics." Materials Science Forum 1045 (September 6, 2021): 102–8. http://dx.doi.org/10.4028/www.scientific.net/msf.1045.102.

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Spark Plasma Sintering (SPS), also known as pulsed electric current sintering (PECS) or field assisted sintering technology (FAST), belongs to a class of powder metallurgy methods. Investigations of the effect of thermal, electric and electromagnetic fields arising under the conditions of spark plasma sintering of ceramic materials on their final characteristics are of important fundamental scientific significance. In this regard, the work investigated the effect of the IPA temperature on the structure, composition and magnetic properties of hematite α-Fe2O3 of high purity 99.995%. Changes in the structure and composition of ceramic specimens under SPS conditions in the temperature range 800-1000°C are described by scanning electron microscopy and X-ray phase analysis. The magnetic properties are studied and the regularities of changes of the magnetization (Ms) and coercive force (Hc) under the influence of an external magnetic field for ceramic samples are determined depending on the temperature of the SPS. These results can be considered as initial study of the process of consolidation of materials with weak ferromagnetism under conditions of spark plasma sintering.

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Soleimani, Sayed Mohamad, Abdel Rahman Alaqqad, Tahir Afrasiab, Adel Jumaah, Ali Behbehani, Abdulaziz Majeed, Mohamad Hazem Al-Swwaf, and Sarah Al-Muhanna. "Utilization of Local Waste Materials in High-Performance and Self-Compacting Concrete." Materials Science Forum 990 (May 2020): 18–28. http://dx.doi.org/10.4028/www.scientific.net/msf.990.18.

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The objective of this study is to investigate the effects of using local waste materials on the properties of fresh and hardened high performance and self-compacting concrete. Crushed ceramic products and steel slag from electric-arc furnaces were used as partial replacements of traditional concrete raw materials in the production of self-compacting and high performance concrete, which were obtained from local factories in Kuwait. Preliminary results have shown that using crushed ceramic products (in the form of powder and 3/8” aggregates) increases the rate of strength gain as the concrete cures, while using electric-arc furnace slag increases the compressive strength of the benchmark concrete mix by up to 40%.

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Minota-Yepes, Isabel Cristina, Román Álvarez-Roca, and Fernando Andrés Londoño-Badillo. "Review: Densification process of ceramic materials." Respuestas 25, no. 2 (May 1, 2020): 199–212. http://dx.doi.org/10.22463/0122820x.2964.

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Ceramics has played an important role in the technological and socio-economic development of humanity, so that they can be used to identify different historical periods of the humanity. Babylonians, Greek, Andalusian, among other cultures have used the ceramics and developed several methods to improve the products obtained by pottery. Generally, the ceramics can be divided into two big areas, traditional and structural ceramics. Ceramics manufactured with clay, Traditional Ceramics, currently they are being studied in the improvement of structural, abrasives, cement, refractory, among other materials. On the other hand, the ceramics developed as a result of new technologies and the exploitation of natural resources, Structural Ceramics, they are a great interest for the science of ceramic materials due to the development of ceramics with properties that incorporate attributes of various materials in only one material, in addition to the contributing to the phenomenological study at a scientific level. Advances in the processes of densification and doping of these materials have allowed to obtain ceramics with high mechanical resistance, high hardness, high resistance to attrition and corrosion, good chemical and thermal stability; features that have directly influenced the type of applications such as bulletproof vests, transparent shields, high temperature electrical insulators, superconducting devices, electronic materials among other applications

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Pietrzak, Tomasz K., Marek Wasiucionek, and Jerzy E. Garbarczyk. "Towards Higher Electric Conductivity and Wider Phase Stability Range via Nanostructured Glass-Ceramics Processing." Nanomaterials 11, no. 5 (May 17, 2021): 1321. http://dx.doi.org/10.3390/nano11051321.

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This review article presents recent studies on nanostructured glass-ceramic materials with substantially improved electrical (ionic or electronic) conductivity or with an extended temperature stability range of highly conducting high-temperature crystalline phases. Such materials were synthesized by the thermal nanocrystallization of selected electrically conducting oxide glasses. Various nanostructured systems have been described, including glass-ceramics based on ion conductive glasses (silver iodate and bismuth oxide ones) and electronic conductive glasses (vanadate-phosphate and olivine-like ones). Most systems under consideration have been studied with the practical aim of using them as electrode or solid electrolyte materials for rechargeable Li-ion, Na-ion, all-solid batteries, or solid oxide fuel cells. It has been shown that the conductivity enhancement of glass-ceramics is closely correlated with their dual microstructure, consisting of nanocrystallites (5–100 nm) confined in the glassy matrix. The disordered interfacial regions in those materials form “easy conduction” paths. It has also been shown that the glassy matrices may be a suitable environment for phases, which in bulk form are stable at high temperatures, and may exist when confined in nanograins embedded in the glassy matrix even at room temperature. Many complementary experimental techniques probing the electrical conductivity, long- and short-range structure, microstructure at the nanometer scale, or thermal transitions have been used to characterize the glass-ceramic systems under consideration. Their results have helped to explain the correlations between the microstructure and the properties of these systems.

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Peláiz-Barranco, A., and Y. González-Abreu. "Ferroelectric ceramic materials of the Aurivillius family." Journal of Advanced Dielectrics 03, no. 04 (October 2013): 1330003. http://dx.doi.org/10.1142/s2010135x1330003x.

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Ferroelectric ceramics are important materials with a wide range of industrial and commercial applications. Since the discovery of the phenomenon of ferroelectricity, they have been the heart and soul of several multibillion dollar industries, ranging from high-dielectric-permittivity capacitors to developments in piezoelectric transducers, pyroelectric sensors, medical diagnostic transducers, electro-optical devices, etc. Materials based on barium titanate and lead zirconate titanate have dominated the field throughout their history. Actually, the ferroelectric ceramics from the Aurivillius family receive great attention due to their large remanent polarization, lead-free nature, relatively low processing temperatures, high Curie temperatures and excellent piezoelectric properties, which made them good candidates for multiple applications. This review presents a general overview of the progress in the studies on the ferroelectric ceramics from the Aurivillius family. The progress includes several aspects: (i) structural studies, (ii) dielectric and electric behavior, (iii) piezoelectricity, and (iv) pyroelectricity.

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Yue, Zhenxing, Jianqiang Zhao, Gang Yang, and Longtu Li. "Electric Field-Dependent Properties of BaTiO3-Based Multilayer Ceramic Capacitors." Ferroelectrics 401, no. 1 (October 29, 2010): 56–60. http://dx.doi.org/10.1080/00150191003670424.

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Qi, Xiaoben, Hailong Shang, Bingyang Ma, Rulin Zhang, Leyang Guo, and Bo Su. "Microstructure and Wear Properties of Micro Arc Oxidation Ceramic Coatings." Materials 13, no. 4 (February 21, 2020): 970. http://dx.doi.org/10.3390/ma13040970.

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The interaction effect of micro arc oxidation (MAO) parameters on the microstructure and wear properties was investigated. The results showed that the electric current and oxidation time significantly influenced the thickness and grinding crack width of the ceramic coatings within the range of the selected parameters, and the interaction effect of the electrical parameters was not obvious. The surface morphology, cross-section morphology, and element distribution of the coatings were observed using scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD). The results showed that ceramic coatings with γ-Al2O3 and α-Al2O3 formed, which enhanced the coating performance. After that, the microhardness and wear resistance were tested. Under the optimal process, the microhardness of a coating section was up to 1200 HV0.1, and the friction coefficient was just 0.3. When wear occurred, the volcanic microstructures experienced extrusion and deformation, and then peeled off under shear stress, which led to the formation of a grinding crack. The main failure modes of the micro arc oxidation coatings were abrasive wear and spalling failure.

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LIU, YANG, ZHUO XU, and YUJUN FENG. "TEMPERATURE-INDEPENDENT DIELECTRIC PROPERTIES OF 0.82[0.94Bi0.5Na0.5TiO3–0.06BaTiO3]–0.18K0.5Na0.5NbO3 CERAMICS." Journal of Advanced Dielectrics 02, no. 01 (January 2012): 1250006. http://dx.doi.org/10.1142/s2010135x12500063.

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In order to explore the high temperature stability of ceramic capacitor, we present temperature-independent dielectric properties of 0.82[0.94Bi0.5Na0.5TiO3–0.06BaTiO3]–0.18K0.5Na0.5NbO3 (BNT–BT–18KNN) ceramics. For different sintered temperature and annealing treatment, the pseudoternary system showed a εr of 2265 at 1 kHz at 35°C with a normalized permittivity ε/ε35°C varying less than ±15% from 11°C to 382°C. This pure perovskite phase with slimmer and heat proof P–E loops possessed energy density of 0.616 J/cm3 with a tolerance of about ±3% in a temperature interval ranging from 20°C to 120°C, which is higher and more temperature stable than most ceramic capacitors, such as PLZST and 0.89BNT–0.06BT–0.05KNN. This relaxor ferroelectric (at room temperature) with parabolic bipolar strain–electric (S(E)) curve showed a quite low temperature dependence of positive strain with less than ±6.5% tolerance from the average value of 0.091% between 20°C and 120°C, which is also more temperature stable than the same composition Zhang et al. reported. These merits demonstrate that the newly produced BNT–BT–18KNN ceramics should be a promising candidate for the development of high-temperature capacitor and actuator materials.

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Betke, Ulf, Katja Schelm, Andreas Rodak, and Michael Scheffler. "Cellular Nickel-Yttria/Zirconia (Ni–YSZ) Cermet Foams: Manufacturing, Microstructure and Properties." Materials 13, no. 11 (May 26, 2020): 2437. http://dx.doi.org/10.3390/ma13112437.

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Open-celled ceramic composite foams were prepared from NiO and yttria-stabilized zirconia (YSZ) powders by the polymer sponge replication (Schwartzwalder) technique using the respective aqueous dispersions. Mechanically stable NiO–YSZ foams with an average porosity of 93 vol.% were obtained. After chemical reduction of the NiO phase with hydrogen, cellular Ni–YSZ cermet structures were obtained. They are characterized by an electric conductivity up to 19∙103 S∙m−1 which can be adjusted by both, the Ni volume fraction, and the sintering/reduction procedure. The NiO–YSZ ceramic foams, as well as the cellular Ni–YSZ cermets prepared therefrom, were characterized with respect to their microstructure by scanning electron microscopy, confocal Raman microscopy and X-ray diffraction with Rietveld analysis. In addition, the compressive strength, the electric conductivity and the thermal conductivity were determined. The collected data were then correlated to the sample microstructure and porosity and were also applied for modelling of the mechanical and electric properties of the bulk Ni–YSZ strut material.

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JEONG, SOON-JONG, JUNG-HYUK KOH, DONG-YOON LEE, JAE-SEOK LEE, MUN-SU HA, JAE-SUNG SONG, and MYOUNG-HO KIM. "EFFECT OF NANOSIZED TiO2 POWDER ON PREPARATION AND PROPERTIES OF Ag-BASED ELECTRODE MATERIALS." International Journal of Nanoscience 03, no. 06 (December 2004): 829–37. http://dx.doi.org/10.1142/s0219581x04002723.

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This study presents the synthesis of nano-oxide-added Ag/Pd powders and its properties tolerable at temperatures above 1100°C for an electrode material utilized in multilayer ceramic devices. The powders of xAg/yPd powder around core cell TiO 2 were formed in a co-precipitation process of Ag and Pd in nano-oxide-dispersed solution, where Ag and Pd precursors are melted in HNO 3 acid. Reaction between ceramic and electrode layers with nanoparticle oxide powder allows internal stress to reduce and mechanical bonding strength to increase due to anchor effect. The densification of the nano-oxide-added electrode paste followed the TiO 2 solid state diffusion-controlled mechanism upon sintering process. The mechanical bonding strength and electrical conductivity were measured after sintering the electrode-printed sheets. As a result, very high adhesive strength over the piezoelectric ceramics' fracture strength and good electrical conductivity of more than 104/Ωcm could be obtained in the multilayer ferroelectric structure which is a form of stacking ceramics layer and electrode layer containing nanoparticles.

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Narkevica, Inga, Jurijs Ozolins, Kristaps Rubenis, Janis Kleperis, Janis Locs, and Liga Berzina-Cimdina. "The influence of thermal treatment conditions on the properties of TiO2 ceramics." World Journal of Engineering 11, no. 2 (June 1, 2014): 131–38. http://dx.doi.org/10.1260/1708-5284.11.2.131.

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The influence of thermal treatment conditions on titanium dioxide ceramics phase transformation, microstructure, physico-mechanical and electrical properties was studied. TiO2 ceramic was prepared using extrusion technology and thermal treatment in air and subsequent annealing under high vacuum conditions. It has been observed that intense TiO2 ceramic mass sintering occurs over the temperature ranging from 950 °C to 1100 °C. It is accompanied by crystallographic modification change from anatase to rutile. Ceramic sample annealing in vacuum causes formation of nonstoichiometric titanium oxide ceramics and as a result electrical conductivity of the material significantly increases. Using extrusion process relatively dense and mechanically resistant ceramic material can be obtained that can be used in different technological processes.

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Karmazin, R., A. Koch, R. Matz, R. Männer, W. Metzger, and A. Wolff. "Dielectrics for Power Capacitors." Additional Conferences (Device Packaging, HiTEC, HiTEN, and CICMT) 2015, CICMT (September 1, 2015): 000015–20. http://dx.doi.org/10.4071/cicmt-ta11.

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High voltage capacitors are key components for transient storage and release of electrical energy in mobile electric devices, electric vehicles, stationary power systems and power transmission. Due to their high electric breakdown voltage, self-healing capability and affordability, polymer-based film capacitors are widely used, particularly those made from biaxially oriented polypropylene (BOPP). Their maximum operating temperature near 100°C, however, requires careful thermal management and oversize design. In high temperature applications well above 200°C, the preference shifts from organic to ceramic dielectric materials. Multilayer ceramic capacitors (MLCCs) are known for their excellent mechanical and thermal robustness, have a mature fabrication technology and have found a wide spectrum of applications in power electronic systems. Their higher cost level is frequently over-compensated by their robustness, a unique selling point particularly in high temperature applications. The present investigation deals with the suitability of various ceramic materials like mica, several high and low temperature sinterable tapes (HTCC, LTCC) as well as atmospheric plasma-sprayed (APS) alumina under such conditions. Aspects of manufacturability and component design are taken into account as well. Dielectric materials performance is particularly addressed by high temperature impedance spectroscopy up to several hundred °C to minimize further self heating of the components above the operating temperature. Although these materials, commercial as well as non-commercial ones, were originally developed for either electric or high temperature applications, the analysis suggests promising materials choices also in cases, when both requirements come together. Although dissipation factors obtained from capacitive test structures cover a wide range, capacitors made from pure alumina (HTCC) generally have lower dielectric loss at all temperatures than those made from glass-ceramic composites (LTCC). Quite diverse properties are obtained with APS alumina, which would represent a promising fabrication alternative due to the possible solid deposition on metal surfaces.

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Iuga, Maria, and Friedrich Raether. "Simulation of the Thermoelastic Properties of Sintered Ceramics." Advances in Science and Technology 45 (October 2006): 89–94. http://dx.doi.org/10.4028/www.scientific.net/ast.45.89.

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Many ceramic materials are composed of various phases, which can differ in their individual thermal, elastic or electrical properties by orders of magnitude. The microstructural arrangement of the phases controls important material properties of the composite. To simulate these macroscopic material properties from the material properties of the constituting phases, a 3-D FEM model is used. The key for an adequate description of real materials is the accurate threedimensional modeling of their microstructure. Basic morphological parameters of many ceramics are reflected by a modified Voronoi model, e.g.: the volume fractions, grain size ratios and contiguity of the phases. By automatically generating thousands of test structures and comparing them to quantitative data derived from image analysis of scanning electron micrographs, structures are selected which closely fit to the microstructure of experimental samples. The model considerations are illustrated on two types of bi-continuous ceramic materials, a porous alumina (Al2O3) and a dense zirconia toughened alumina (ZTA) ceramic. Using different volume fractions of the phases, Voronoi type microstructures and truncated sphere models are exemplified. For these two ceramic systems, elastic moduli and thermal conductivity are calculated and compared to experimental data of samples of the respective microstructure.

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Guillon, Olivier, Roger A. De Souza, Tarini Prasad Mishra, and Wolfgang Rheinheimer. "Electric-field-assisted processing of ceramics: Nonthermal effects and related mechanisms." MRS Bulletin 46, no. 1 (January 2021): 52–58. http://dx.doi.org/10.1557/s43577-020-00008-w.

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AbstractField-assisted processing methods, such as spark plasma sintering and flash sintering, have considerably expanded the toolbox of ceramic engineering. Depending on the conditions, substantial electric currents may flow through the material resulting in fast heating rates due to Joule heating. Here, we focus on nonthermal effects induced by electric fields during processing of fluorite- and perovskite-based ceramics. The fundamentals of how a field can directly modify defect formation and migration in crystals are discussed. In addition, the interplay of ion transport and electrical conductivity is considered, this interplay being crucial to understanding nonthermal effects caused by electric fields (as in memristive switching). Electrochemical reactions leading to new phases or reduction are also described, as are densification rates and sintering parameters that are significantly affected even though the sample temperature is held constant. Finally, as grain-boundary properties and segregation are changed by ion transport, we describe how both retardation and acceleration of grain growth can be achieved including graded microstructures.

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Liang, Li. "Mechanical properties analysis and microstructure of ceramic materials of mullite ceramic material." International Journal of Electrical Engineering & Education 56, no. 4 (October 14, 2018): 293–304. http://dx.doi.org/10.1177/0020720918803709.

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Albert, Etele, Marcela Muntean, A. Ianculescu, Florin Miculescu, and B. Albert. "Special Ceramic Material Based On Basaltic-Andesite for Extreme Environments." Advanced Materials Research 59 (December 2008): 39–41. http://dx.doi.org/10.4028/www.scientific.net/amr.59.39.

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A special ceramic material with specific performances for some extreme environments can be elaborated using basaltic-andesite as raw material. The volcanic rocks presents specific compositions, a complex structure and properties, so some of them, such as basaltic-andesite, may have multiple utilization. The elaborated basaltic-andesite compound ceramic material, in mixture with porcelain-clay and alumina was characterized with SEM (scanning electron microscopy), EDS (energy dispersive spectroscopy), X-ray diffraction and thermo-gravimetric analysis. Many of the properties of this sort of ceramic material surpass the electric insulator porcelain type KER 110 ceramic, and in some approximate the high alumina-content ceramic materials.

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Kozík, Tomáš, and Stanislav Minárik. "New Possibilities for Investigation of the Technological Texture Based on Measurement of Electric Parameters: Theoretical Analysis and Experimental Verification." Journal of Electrical Engineering 64, no. 6 (November 1, 2013): 376–80. http://dx.doi.org/10.2478/jee-2013-0057.

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Abstract Texture is preferred orientation of crystallites in some polycrystalline materials. Different methods are applied to characterize the orientation patterns and determine the orientation distribution. Most of these methods rely on diffraction. This paper introduces the principle of a method used for characterization of ceramics texture based on anisotropy of electrical properties of crystallites in ceramics. The mathematical framework of this method is presented in theoretical part of our work. In experimental section we demonstrate how the theoretical result could be used to evaluate technology texture of ceramic material intended for the production of electronic insulators.

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Sirilar, Pakawadee, Nakorn Srisukhumbowornchai, Purit Thanakijkasem, Somnuk Sirisoonthorn, and Gernot Klein. "Thermal and Physical Properties of White-Opaque Sanitary Glazes Using Lampang Pottery Stone as Raw Materials." Materials Science Forum 872 (September 2016): 118–22. http://dx.doi.org/10.4028/www.scientific.net/msf.872.118.

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The aim of this work was to determine thermal and physical properties of white-opaque sanitary glazes. Lampang pottery stone was used to replace silica (G2) and feldspar (G3) in the commercial sanitary glaze (G1). All formulations of glazes developed from Seger formula calculation and the glaze slurry was prepared by wet milling, green glazing on commercial ceramic body and firing at 1200๐C with heating rate of 3๐C/min by using electric kiln. Melting characteristics, specular gloss, lightness, color, and thermal expansion behavior of all sanitary glazes were investigated. As a result, the glaze G2 was a good reflecting surface with high lightness value. Linear thermal expansion difference at 500๐C between the glaze G2 and the commercial ceramic body was-0.015%. This glaze-body fit was, therefore, under small compression and more compatible to ceramic sanitary products.

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Fényi, B., N. Hegman, F. Wéber, P. Arató, and Cs Balázsi. "DC conductivity of silicon nitride based carbon-ceramic composites." Processing and Application of Ceramics 1, no. 1-2 (2007): 57–61. http://dx.doi.org/10.2298/pac0702057f.

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Abstract:

The silicon nitride ceramics are usually known as strongly refractory and enduring materials and have typical electrically insulating properties. If the reinforcing phase of ceramic composite (that is mainly put in the material to improve mechanical properties) is a good electrical conductor, it is worth to investigate the composite in electrical aspect. In this work carbon nanotubes, black-carbon and graphite were added to the basic silicon nitride ceramic and the electrical conductivity of the prepared carbon-ceramic composites was determined. The conductivity of the ceramic composites with different type and concentration of the carbon additives was observed by applying four point DC resistance measurements. Insulator and conductor composites in a wide conductivity range can be produced depending on the type and quantity of the additives. The additive types as well as the sintering parameters have influence on the basic electrical properties of the conductor composites.

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Journal articles on the topic 'Ceramic materials - Electric properties'

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