Browsing Bildiri Koleksiyonu by Author "Kara, Ferhat"
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alpha/beta SiAlON BASED COMPOSITES INCORPORATED WITH MoSi2 FOR ELECTRICAL APPLICATIONS
Ayas, Erhan; Kara, Alpagut; Kara, Ferhat (Amer Ceramic Soc, 2010)Electrically conductive alpha-beta SiAlON composites containing 30 vol. % MoSi2 was prepared by gas pressure sintering (GPS). The effect of sintering atmosphere on phase formation, grain growth, mechanical and electrical ... -
Development of alpha-beta SiAlON ceramics from different Si3N4 starting powders
Açıkbaş, N. Çalış; Kara, Ferhat; Mandal, Hasan (Trans Tech Publications LTD, 2009)alpha-beta SiAlON ceramics were produced from different starting Si3N4 powders including beta-Si3N4 and alpha-Si3N4 powders and mixtures of these powders. Gas pressure sintering was used for sintering. After sintering, ... -
Development of laminar type functionally graded SiAlON ceramics
Çalış, N; Kara, Alpagut; Kara, Ferhat; Mandal, Hasan (Trans Tech Publications LTD, 2004)In order to combine high hardness with high toughness, laminar type (two layers) functionally graded (FGM) SiAlON ceramics were developed. In a previous study achieved by the same authors, presence of a sharp transition ... -
Development strategies for sialon ceramics
SiAlON ceramics have a wide range of applications due to their favorable mechanical and thermal properties. They are one of the main groups of materials being considered for high temperature load bearing applications and ... -
Functionally graded SiAlON ceramics
Çalış, N; Kuşhan, Seniz Reyhan; Kara, Ferhat; Mandal, Hasan (Elsevier Sci LTD, 2004)Functionally graded SiAlON ceramics were developed by three different methods to improve the mechanical properties of SiAlONs; powder bed, rapid cooling and laminating. beta-SiAlON compacts were embedded in two different ... -
Fundamentals for optimization of binding for high refractory mullite products
Başpınar, M. Serhat; Schulle, W; Kara, Ferhat (Trans Tech Publications LTD, 2004)Properties of the binder matrix affect the quality of the refractory. Better qualities are possible if the binding is optimum. Mechanical properties, thermal shock resistance, creep and corrosion behaviour of the mullite ... -
Glass-ceramic glazes in the CaO-SiO2 system
Alptekin, K; Kara, Ferhat (Trans Tech Publications LTD, 2004)Glass ceramic glazes were developed in the system of CaO-SiO2 system. Compositions containing B2O3 and K2O as fluxing agent were melted at 1450degreesC and fritted. Glazes for porcelain tiles were formulated by using these ... -
Influence of type of cations on intergranular phase crystallisation of SiAlON ceramics
Açıkbaş, N. Çalış; Kara, Alpagut; Turan, Servet; Kara, Ferhat; Mandal, Hasan; Bitterlich, B. (Trans Tech Publications LTD, 2007)25 alpha:75 beta SiAION composition was designed with different cations and at different molar ratios. Effect of the type of cations both on the composition and the type of intergranular phase investigated after gas pressure ... -
Interactions Between AlN and SiAlON Ceramics
Kalemtaş, Ayşe; Acikbas, N. Çalış; Kara, Ferhat; Mandal, Hasan; Krnel, K.; Kosmac, T. (Trans Tech Publications LTD, 2009)In the present study, interactions between AlN and SiAlON laminated couples were investigated after gas pressure (GPS) and spark plasma sintering (SPS) by scanning electron microscopy (SEM) and energy dispersive x-ray ... -
Joining of SiAlON ceramics to pyrex glass
Kalemtaş, Ayşe; Kara, Alpagut; Kara, Ferhat; Mandal, Hasan; Aktug, B (Belgian Ceramic Society, 2004)In the present study, pressureless joining of gas pressure sintered (alpha-beta)-SiAlON ceramics to pyrex glass was investigated. Preoxidized SiAlON ceramics were used to enhance wettability and provide chemical compatibility ... -
Mechanical characterization of highly porous beta-Si3N4 ceramics fabricated via partial sintering & starch addition
Kalemtaş, Ayşe; TopAteş, Gülsüm; özcoban, Hüseyin; Mandal, Hasan; Kara, Ferhat; Janssen, Rolf (Elsevier Sci LTD, 2013)In this study, porous beta-Si3N4 ceramics containing limited amount of Sm2O3 and CaO as sintering aids were produced by addition of potato starch (10 and 20 vol.%) and partial sintering. Two different Si3N4 powders, alpha- ... -
Microstructure-permeability relation of porous beta-Si3N4 ceramics
Topateş, Gülsüm; Mammitzsch, Lars; Petasch, Uwe; Adler, Joerg; Kara, Ferhat; Mandal, Hasan (Elsevier Sci LTD, 2013)Porous beta-Si3N4 ceramics with two distinct structures were produced by using two different Si3N4 sources to investigate the relationship between microstructure and permeability. Results showed that regardless of pore ... -
A Novel Approach For Preparing Electrically Conductive SiAlON-TiN Composites by Spark Plasma Sintering
Ayas, Erhan; Kara, Alpagut; Kara, Ferhat (Trans Tech Publications LTD, 2009)An effective approach for preparing electrically conductive SiAlON-TiN composites was developed. Granules of a designed composition of alpha-beta SiAlON was obtained by spray drying and coated with varying amounts of TiO(2) ... -
Pressing behaviour of spray dried alumina-zirconia granules
Kara, Ferhat; Kara, Alpagut; Turan, Servet; Mandal, Hasan (Trans Tech Publications LTD, 2004)In this study, spray drying of alumina-zirconia slurries on a pilot scale, and their pressing behaviour were investigated. Slurries were prepared at 50 wt-% solid loading. An acrylic polymer emulsion, polyethylene glycol, ... -
Pressureless Melt Infiltrated Non-Oxide Ceramic-Metal Composites
Kalemtaş, Ayşe; Arslan, Gökhan; Kara, Ferhat (Trans Tech Publications LTD, 2009)In the present study highly dense (open porosity < 1 %), light-weight (d <= 2.85 g/cm(3)) and Al(4)C(3)-free non-oxide ceramic-metal composites were produced at comparatively low temperatures (<= 1250 degrees C) by pressurless ... -
Production of alpha-beta SiAlON-TiN/TiCN composites by gas pressure sintering
Ayas, Erhan; Kara, Alpagut; Mandal, Hasan; Turan, Servet; Kara, Ferhat (Belgian Ceramic Society, 2004)Due to the favorable properties possessed by novel alpha-beta SiAlONs, they are attractive materials for cutting tool applications. Such applications require materials with high hardness, high fracture toughness and high ... -
Reaction model for the boron carbide/aluminium system
Arslan, Gökhan; Kara, Ferhat; Turan, Servet (Trans Tech Publications LTD, 2004)An attempt has been made to shed light on the reaction mechanism during the production of B4C/Al composites by making use of the measured phase contents of the phases B4C, Al, Al3BC and AlB2. It was found that the agreement ... -
Spark plasma sintering of Si3N4-B4C composites
Ayas, Erhan; Kalemtaş, Ayşe.; Arslan, Gökhan; Kara, Alpagut; Kara, Ferhat (Ceramic Soc Japan-Nippon Seramikkusu Kyokai, 2008)In this study the production Of Si3N4-B4C Composites using spark plasma sintering technique was studied. This technique was preferred in order to minimize the reactions between starting constituents. Fully dense Si3N4 ... -
Spark Plasma Sintering of Silicon Nitride-Boron Carbide Composites
Ayas, Erhan; Kalemtaş, Ayşe.; Arslan, Gökhan; Kara, Alpagut; Kara, Ferhat (Trans Tech Publications LTD, 2009)Si(3)N(4)-B(4)C composites containing fine and coarse B(4)C particles were produced using Al(2)O(3) and Y(2)O(3) as sintering additives via spark plasma sintering (SPS) technique. Phase assemblages of the produced composites ... -
?/ß SiAlON based composites incorporated with MoSi2 for electrical applications
Ayas, Erhan; Kara, Alpagut; Kara, Ferhat (2010)Electrically conductive ?-ß SiAlON composites containing 30 vol. % MoSi2 was prepared by gas pressure sintering (GPS). The effect of sintering atmosphere on phase formation, grain growth, mechanical and electrical properties ...