Papers by Keyword: Ceramic Material

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Authors: Kiyoshi Suzuki, Tetsutaro Uematsu, Manabu Iwai, Shinichi Ninomiya, Sadao Sano, Takeo Nakagawa
Abstract: A new complex grinding method named Ultrasonic Electrodischarging Grinding Method (US-ED-G in short) is described. In the US-ED-G, ultrasonic grinding and ED grinding are simultaneously carried out on an electrically conductive workpiece with a metal bond grinding wheel. When compared with other complex grinding methods, the US-ED-G is remarkably effective in reducing grinding force a great deal and maintaining grinding ability of a wheel for a long time in efficient grinding of extremely hard-to-grind ceramic materials like TiB2. A stock removal rate of 200mm3/min and a grinding ratio of 110 have been attained by selecting appropriate conditions in US-ED-G of TiB2. A compact and rigid ultrasonic attachment is also described, which was developed as a removable tool for carrying out US grinding and US-ED-grinding on a machining center or a grinding center.
Authors: Yan Xia Feng, Chuan Zhen Huang, Jun Wang, H.T. Zhu
Abstract: In this paper, the micro-topography of the milled surface and chips are investigated, and the milling mechanisms of ceramics are analyzed. The results show that there are many deep and flat craters due to material fractures on the milled surface of Al2O3 ceramics and evidence of plastic flow is also observed around the craters. The milled surface of Si3N4 ceramics is smooth and even, and the trace of plastic flow can be observed. The abrasives after milling are very different from those before milling, which reflects the strong impact between abrasives and materials during the milling process. It is shown that the dominant milling mechanisms of ceramics are crack and exfoliating due to brittle fracture and plastic distortion according to the form of the chips.
Authors: Ming Yuan Wang, Fang Zhao, Jun Shou Li, Su Li, Xiao Juan Wu
Abstract: Using TiO2B2O3 powders as oxidizer,AlMg powders as reducer,the TiB2 multiphase ceramic are preparated with SHS, and analysed with SEM and XRD.The effect of HCl, H3PO4 to pickling of TiB2-based multiphase ceramics is explored by SEM and XRD analysis. Research suggests that: the main ingredients of TiB2-based multiphase ceramics is TiB2, MgO and MgAl2O4 three phases, few of reaction residual objects and impurities also exists; the multiphase ceramics is forming by many of hexagonal crystal type products and small particles reunion, hexagonal crystal type product is TiB2, small particles may be MgO, MgAl2O4 and other impurities product; MgO can be effectively washed by HCl and H3PO4 , but TiB2 and MgAl2O4 invalid. At room temperature, 30% HCl pickling has the best effect, the concentration of TiB2(ω) is up to 59.3%; the higher of the concentration, the better of acid-effect; In the pickling process, as the temperature rises, the concentration of TiB2 grows, but the temperature should not be too high. When temperature reach 75 °C, HCl volatilizes too quickly and inefficiently. At room temperature, 20% H3PO4 has the best pickling effect, the concentration of TiB2(ω) is up to 52.6%, but the best pickling effect is not well with concentration increasing; as the temperature increasing, purity of TiB2 is also increased; At 70°C, the concentration of TiB2(ω) after H3PO4 pickling is up to 61.9%, refine effect is good.
Authors: Giuseppe Pezzotti, Atsuo Matsutani, Maria Chiara Munisso, Wen Liang Zhu
Abstract: With the proliferation of several types and classes of high performance ceramic materials, the screening, evaluation and integration of new materials into structures and devices require a new and more effective approach. Evaluation on the nano-scale of the mechanical characteristics of new ceramic materials requires multiple complementary metrology tools. We report here about an advanced metrology tool, cathodoluminescence (CL) spectroscopy, which has a potential to rapidly screen and evaluate residual stress characteristics in advanced ceramic materials and structures. Nano-scale stress measurements are made in situ into an integrated metrology vacuum chamber in a field-emission gun scanning electron microscope (FEG-SEM). Complementing this tool, we also describe a new image analysis based on CL emission for fast screening and ranking of domain structures in ferroelastic ceramics. The end result of this paper is to show how crystallographic and mechanical characteristics of ceramics can be quantitatively characterized in a hybrid device combining electro-stimulated imaging and spectroscopic outputs.
Authors: E. Uhlmann, C. Hübert
Abstract: The competitiveness of component parts made of advanced ceramics results almost exclusively from the properties of the material in use. However, it is restricted by the constantly high costs of part manufacture especially in the finishing stage. The results of recent investigations being presented in this paper demonstrate an increase in productivity of material removal via the application of the innovative technology of ultrasonic assisted grinding. During the manufacture of through holes or grooves in ceramic materials such as Al2O3, Zr2O, SSN and SiC this process is characterized by significant less process forces and lower process temperatures in comparison with conventional grinding processes. In order to deepen the process knowledge of this modified grinding process two different simulation tools have been introduced. A voxel-based approach for modeling of the material removal as well as CFD-simulation of the unique cooling lubricant flow conditions proved their capability as an optimization tool.
Authors: Alan de Oliveira Feitosa, José Elson Soares Filho, Leonardo Leandro dos Santos, Romualdo Rodrigues Menezes, Ricardo Peixoto Suassuna Dutra
Abstract: Color is a very important characteristic in ceramic products. In ceramic coatings, the basis of ceramic is normally classified as red or white basis. Another relevant factor for color variation is the processing to which the material is submitted. In this sense, this work aims to analyze and quantify the color of ceramic pieces used as coatings, which were developed from a formulation of masses, using raw materials such as clay, feldspar, kaolin and quartz. Each raw material was analyzed separately and then a standard formulation was made, involving all of them, and these ones were submitted to different processing temperatures. All the samples were quantified regarding the color, by using the tridimensional colorimetric space by CIELAB method. Results point out that each raw material has an own value regarding color and the temperature has contributed directly to the color variation of the ceramic pieces.
Authors: Jia Liang Wang, De Jun Ma, Wei Chen, Yong Huang, Liang Sun
Abstract: Based on the finite element analysis method, the relationship between two systems of crack (radial crack and lateral crack) and pop-in phenomenon were compared during the instrumented indentation process in ceramic materials. In order to give a reasonable explanation for mechanism analysis of pop-in phenomenon in the process of ceramic materials instrumented indentation, this paper proposed the viewpoint that pop-in phenomenon is caused by the lateral crack in the process of ceramic materials instrumented indentation. This work provided a theoretical basis for the study of instrumented indentation methodologies based on the pop-in phenomenon to determining mechanical properties of ceramic materials.
Authors: Yong Zheng, Bai Yang Jin
Abstract: Jinjiu’s ceramic bottle has been in China’s wine market for a few years, and the choice of ceramics reflects traditional Chinese design idea of “combination of object and practicability, and manifestation of life with object”, which satisfies consumers’ requirements about national traits, style and taste of wine. This paper will analyze how Jiujin Group skillfully adopted China’s traditional ceramic technology to the design of package and explore a successful way of national package of wine through the example of Jiujin.
Authors: Jose L.G. Fierro, Barbara Pawelec
Abstract: This contribution aims to provide a general overview of the potential of ceramic materials in several areas related to energy production and storage. Ceramic materials for both low and high temperature fuel cells are examined in some detail. Engineered, porous, ceramic support loaded with noble metals are particularly suited to address the material limitations encountered with wash-coated, metal-based, catalyst supports. These materials demonstrated high-performance and resistance under severe operation conditions. Metal oxides and carbides present high stability in a fuel cell environment and acceptable electrical conductivity, but most of them possess a low specific area. In addition, H2 production by water splitting on ceramic oxides of the type ferrites, YSZ and other supported systems will be examined. Finally, a few aspects of the new nanoscale ceramics for batteries of higher storage capacity and storage capacitors will also be presented.
Authors: Chong Hai Xu, Jing Jie Zhang, Zhen Yu Jiang, Ming Dong Yi
Abstract: In the die manufacturing process of ceramic extrusion die, the residual stress was produced resulted from the thermal expansion coefficient mismatch between ceramic die and die core of graphite. As a result, the longitudinal cracks were formed in the ceramic extrusion die. The thermal residual stress formed in the cooling process was analyzed by finite element simulation method. The result indicated that the thermal expansion coefficient was the primary factor which could affect the tensile stress of ceramic extrusion die. Then, the thermal expansion coefficient, elastic modulus and poisson's ratio of ceramic extrusion die material were selected as design variables, and the largest tensile stress that less than allowable stress of ceramic die material was determined as the objective function, the material component were optimized according to the finite element simulation. The longitudinal cracks were eventually avoided.
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