Yazar "Mandal, Hasan" için Bildiri Koleksiyonu listeleme
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The design of compositions for multi-cation doped ?-ß SiAlON ceramics by the Rietveld method
Kurama, Semra; Herrmann, M.; Mandal, Hasan (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 ... -
The design of compositions for multi-cation doped alpha-beta SiAlON ceramics by the Rietveld method
Kurama, Semra; Herrmann, M; Mandal, Hasan (Trans Tech Publications LTD, 2003)Although densification of alpha-beta-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 ... -
The effect of different nucleation temperatures on the grain morphology of ?-SiAlON ceramics
Kuşhan, Seniz Reyhan; Mandal, Hasan (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 ... -
The effect of different nucleation temperatures on the grain morphology of alpha-SiAlON ceramics
Kuşhan, Seniz Reyhan; Mandal, Hasan (Trans Tech Publications LTD, 2003)Nitrogen rich yttrium-cerium containing multi-cation alpha-SiAlON starting compositions were prepared by gas pressure sintering using conventional alpha-Si3N4 powder. Microstructural characterization of the two stage ... -
Effect of starting Si3N4 powder type and sintering conditions on the grain morphology of ?-SiAlON ceramics
Kuşhan, Seniz Reyhan; Mandal, Hasan (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 ... -
Effects of different Si3N4 starting powders and sintering conditions on the grain morphology and mechanical properties of ?-SiAlON ceramics
Kuşhan, Seniz Reyhan; Mandal, Hasan (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 ... -
Effects of different Si3N4 starting powders and sintering conditions on the grain morphology and mechanical properties of alpha-SiAlON ceramics
Kuşhan, Seniz Reyhan; Mandal, Hasan (Trans Tech Publications LTD, 2002)Nitrogen rich yttrium-cerium containing multi-cation alpha -SiAlON starting compositions have been prepared by gas pressure sintering using "conventional" alpha -Si3N4 or alpha-beta Si3N4 containing powder. The effect of ... -
Hard and tough alpha-SiAlON ceramics
Mandal, Hasan; Hofmann, J. Michael (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 ... -
Improvement of elongated ?-SiAlON ceramics by variation of the processing conditions and amounts of additives
Kurama, Semra; Herrmann, M.; Mandal, Hasan (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 ... -
Improvement of elongated alpha-SiAlON ceramics by variation of the processing conditions and amounts of additives
Kurama, Semra; Herrmann, M; Mandal, Hasan (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 ... -
New developments in alpha-SiAlON ceramics
Mandal, Hasan (Elsevier Sci LTD, 1999)Two different alpha-sialon compositions have been densified by either pressureless sintering or capsul-free sinter HIPing using either single cation namely strontium, lanthanum, cerium, neodymium or their equimolar mixtures ... -
Novel developments in alpha-SiAlON ceramics
Mandal, Hasan; Hofmann, J. Michael (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 ... -
Novel SiAlON ceramics for cutting tool applications
Mandal, Hasan; Kara, Ferhat; Turan, Servet; Kara, Alpagut (Trans Tech Publications LTD, 2003)New alpha-beta SiAlON ceramics were produced in aqueous medium by Using Multiple oxides as densifying additives. The sintered materials were characterised using a combinations of techniques such as XRD, SEM and TEM. The ... -
Performance of new ?-ß SiAlONs in turning operations
Mandal, Hasan; Kara, Ferhat; Turan, Servet; Kara, Alpagut (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 ... -
Performance of new alpha-beta SiAlONs in turning operations
Mandal, Hasan; Kara, Ferhat; Turan, Servet; Kara, Alpagut (Trans Tech Publications LTD, 2002)New alpha-beta 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 ... -
The preparation of Ce alpha-sialons and related unstable phases
Thompson, DP; Mandal, Hasan (Iom Communications LTD, 1998)It has previously been accepted that lanthanum and cerium do not form alpha-sialon structures because their ions are too large to enter the interstices in the structure. Recent work on heat-treatment of rare-earth densified ... -
Transmission electron microscopy of SrO containing multi-cation doped ?-SiAlON ceramics
Turan, Servet; Mandal, Hasan; Kara, Ferhat (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 ... -
Transmission electron microscopy of SrO containing multi-cation doped alpha-SiAlON ceramics
Turan, Servet; Mandal, Hasan; Kara, Ferhat (Trans Tech Publications LTD, 2002)An advantage of alpha-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 ... -
Transmission electron microscopy studies of La2O3-doped alpha-SiAlON ceramics
Turan, Servet; Mandal, Hasan; Kara, Ferhat; Knowles, KM (IOP Publishing LTD, 1999)alpha-SiAlON is able to accommodate cations into its crystal structure if the cations are sufficiently small in size, thus helping to reduce the volume of the remnant grain boundary phase after processing. In this study, ...