Bildiri Koleksiyonu: Recent submissions
Now showing items 1-20 of 40
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The design of compositions for multi-cation doped ?-ß SiAlON ceramics by the Rietveld method
(2003)Although densification of ?-ß-SiAlON ceramics is easier by using sintering additives, it is difficult to achieve the designed composition and therefore the mechanical properties after sintering. This is mainly due to the ... -
Transmission electron microscopy of SrO containing multi-cation doped ?-SiAlON ceramics
(2002)An advantage of ?-SiAlON is that it can accommodate cations of sintering additives and hence reduces the amount of deleterious remnant intergranular amorphous phase. However, it is believed that relatively large cations ... -
Effect of starting Si3N4 powder type and sintering conditions on the grain morphology of ?-SiAlON ceramics
(2002)Nitrogen rich neodymium-ytterbium containing multi-cation ?-sialon starting compositions have been prepared by gas pressure sintering using "conventional" ?-Si3N4 or plasma produced ß-Si3N4 powder. The effect of ?-SiAlON ... -
Improvement of elongated ?-SiAlON ceramics by variation of the processing conditions and amounts of additives
(2001)Two types of Y-?-SiAlON composition, with different amounts of additional liquid phase were densified in a gas pressure sintering furnace using three different sintering cycles. One series of samples was heated up to 1825°C ... -
Performance of new ?-ß SiAlONs in turning operations
(2001)New ?-ß SiAlON ceramics were produced, characterised and tested in turning operations of cast iron. Cutting speeds varied between 400-1200 m/min while feeding rates were between 0.3 to 0.5 mm/rev. The results were compared ... -
Effects of different Si3N4 starting powders and sintering conditions on the grain morphology and mechanical properties of ?-SiAlON ceramics
(2001)The preparation of ?-SiAlON microstructures by ß-Si3N4 starting powder or by applying nucleation step during sintering was studied. The application of sintering cycles on nucleation effect and the effect of different Si3N4 ... -
The effect of different nucleation temperatures on the grain morphology of ?-SiAlON ceramics
(2003)Nitrogen rich yttrium-cerium containing multi-cation ?-SiAlON starting compositions were prepared by gas pressure sintering using conventional ?-Si3N4 powder. Microstructural characterization of the two stage sintered ... -
Transmission electron microscopy of interfaces in structural ceramic composites
(Blackwell Science LTD, 1999)Ceramic composites based either on a particulate, fibre or a lamellar architecture are potentially useful as damage-tolerant high-temperature engineering materials. The ability of the interfaces in such systems to deflect ... -
Piezoelectric hollow spheres for microprobe hydrophones
(Taylor & Francis LTD, 1999)Miniature hollow spheres of lead zirconate titanate have been prepared with a coaxial nozzle process using fine grain slurry of PZT-5. Following the binder burnout and sintering, the spheres were poled radially and ... -
Functional composites for sensors, actuators and transducers
(Elsevier Sci LTD, 1999)Following the trend in structural applications, composite structures are being used more commonly in transducer applications to improve acoustic, mechanical and electrical performance of piezoelectric devices. Functional ... -
Preparation and fracture behavior of alumina platelet reinforced alumina-monazite composites
(Japan Inst Metals, 2002)Fracture behaviors were investigated in the laminated alumina composite ceramics. To improve the mechanical properties of alumina ceramics, templated grain growth (TGG) technique of alpha-Al2O3 platelet and LaPO4 as a ... -
Interphase boundaries between hexagonal boron nitride and beta silicon nitride in silicon nitride silicon carbide particulate composites
(Elsevier Sci LTD, 1997)Interphase boundaries between hexagonal boron nitride and beta-Si3N4 in hot isostatically pressed Si3N4-SiC particulate composites, in which boron nitride appears as a trace contaminant, have been examined using high ... -
Hydrothermal synthesis of lead titanate and lead zirconate titanate electroceramic particles
(Taylor & Francis LTD, 2003)Hydrothermal synthesis of two lead-based perovskite powder systems, lead titanate and lead zirconate titanate, was investigated. Phase-pure perovskite lead titanate and lead zirconate titanate with various morphologies ... -
Novel developments in alpha-SiAlON ceramics
(Trans Tech Publications LTD, 2000)Densification and stabilization of alpha-sialon ceramics have been investigated by using oxides of large cations (Sr2+, La3+, Ce3+, Nd3+) and their equimolar mixtures with calcium or ytterbium as a principal cation. All ... -
Hard and tough alpha-SiAlON ceramics
(Trans Tech Publications LTD, 2000)Yb, Nd/Ca and Ce/Ca containing a-sialon starting compositions have been densified by either pressureless sintering or capsul free sinter/HIP'ing using "conventional" alpha-Si3N4 powder. X-ray diffraction studies of both ... -
Wetting and non-wetting behaviour of silicon carbide grain boundaries
(Transtec Publications LTD, 1999)Silicon carbide (SiC) grain boundaries have been observed to be free from intergranular films. On the basis of equilibrium film thickness calculations, it has been proposed elsewhere that because SiC has very high refractive ... -
Capacitor discharge joining of silicon carbide based ceramics
(Trans Tech Publications LTD, 2002)A capacitor-discharge joining technique has been successfully used to join oxide ceramics using thin metal foils. In this study, silicon carbide (SiC) ceramic joints and silicon carbide-titanium diboride (TiB2) composite ... -
Orientation-dependent equilibrium film thickness at interphase boundaries in ceramic-ceramic composites
(IOP Publishing LTD, 1997)Theoretical considerations of the Hamaker constant for the interaction of two media across a third suggest that the highly anisotropic nature of the refractive indices of a medium such as h-BN will produce an orientation ... -
Improvement of elongated alpha-SiAlON ceramics by variation of the processing conditions and amounts of additives
(Trans Tech Publications LTD, 2002)Two types of Y-alpha -SiAlON composition, with different amounts of additional liquid phase were densified in a gas pressure sintering furnace using three different sintering cycles. One series of samples was heated up to ... -
Hydrothermal synthesis of tabular perovskite particles
(Trans Tech Publications LTD, 2002)Phase pure perovskite lead titanate and lead zirconate titanate powders were produced by hydrothermal synthesis. Reaction temperature and time are critical processing parameters for formation of phase-pure perovskite ...
