TY - CONF A1 - Eberstein, Markus A1 - Dernovsek, O. A1 - Nicolaides, Dagmar A1 - Schiller, Wolfgang Arno T1 - Modifikation von La2O3-B2O3-TiO2-Gläsern zur Einstellung von Mikrowelleneigenschaften niedrigsinternder Dielektrika T2 - 75. Glastechnische Tagung CY - Wernigerode, Deutschland DA - 2001-05-21 PY - 2001 SP - 301 EP - 305 PB - DGG, Deutsche Glastechnische Gesellschaft e.V. CY - Frankfurt/M. AN - OPUS4-1651 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Wäsche, Rolf A1 - Yarim, Rasim A1 - Nicolaides, Dagmar T1 - Influence of Green Compaction on the Sintering Behaviour of SiC-TiC-TiB2 Composites KW - Pressureless sintering KW - SiC KW - TiC KW - TiB2 KW - Green compaction KW - Particle size KW - Microstructure PY - 2004 SN - 1013-9826 VL - 264-268 SP - 213 EP - 218 PB - Trans Tech Publ. CY - Aedermannsdorf AN - OPUS4-12054 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dombrowski, Felix A1 - Marx, Heidi A1 - Ploska, Ute A1 - Nicolaides, Dagmar A1 - Stiller, M. A1 - Knabe, C. A1 - Berger, Georg T1 - Solubility and ingrowth behaviour of degradable and figuline calcium alkaline phosphate cements N2 - The thrust of the investigations presented here is to point out the degradation behaviour in vitro and the ingrowth behaviour in vivo of four different calcium alkaline phosphate cements. Two of the figuline and mouldable composites consist of the crystalline phase Ca2KNa(PO4)2 and two of the crystalline phase Ca10[K/Na](PO4)2 each containing 2wt% medium gel strength porcine gelatin. Furthermore A-TCP was added to both Ca10[K/Na](PO4)2 cements as a hardening supporting reactant. The testing material groups differ in small amorphous portions containing either silica phosphate (GB9), magnesium potassium phosphate (GB14) or diphosphates (401545 and 401545(70)). The respective composites show a monomodal particle size distribution (d50~7µm; span~4) and an average total porosity around 28vol%.For the solubility studies cylindrical samples (d=6mm; h=12mm) were stored in a 0.1mol TRIS buffer solution and incubated at 37°C for maximum 50 weeks. The storage solution was analysed and renewed every week. The results are plotted cumulative. For the in vivo studies critical size defects were dissected to mandibles in a sheep model in which a 1cm³ area of the bottom of the mandibles was surgically resected and replaced with the figuline cements whereas the mouldability allows the reconstruction of the original outer contour without draining off even when replacing upside down. KW - Calcium alkaline phosphate cement KW - Gelatin KW - Figuline KW - Solubility KW - Ingrowth behavior PY - 2012 U6 - https://doi.org/10.4028/www.scientific.net/KEM.493-494.387 SN - 1013-9826 VL - 493-494 SP - 387 EP - 390 PB - Trans Tech Publ. CY - Aedermannsdorf AN - OPUS4-24924 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dressler, M. A1 - Börnstein, Julian A1 - Meinel, M. A1 - Ploska, Ute A1 - Reinsch, Stefan A1 - Hodoroaba, Vasile-Dan A1 - Nicolaides, Dagmar A1 - Wenzel, Klaus-Jürgen T1 - Sol-gel preparation of calcium titanium phosphate: viscosity, thermal properties and solubility N2 - Calcium titanium phosphate (CTP) was prepared by the sol–gel route in order to prepare suitable coatings. This work addresses the question of how to prepare stable CTP sols. Their rheological properties as a function of process parameters like solid loading and water content are investigated. It was found that an increased solid loading as well as an increased water content lead to an increased initial viscosity as well as a more pronounced ageing induced viscosity rise. In addition, the thermal behavior of the resulting xerogels was analyzed. Furthermore, we studied the ion release behavior of the xerogels when brought in contact with water. Results suggest that calcium titanium phosphate shows a diffusion controlled ion release mode with a preferential release of Ca. KW - Calcium titanium phosphate KW - Sol-gel processing KW - Rheology KW - Thermal analysis KW - Coatings KW - Solubility PY - 2012 U6 - https://doi.org/10.1007/s10971-011-2653-y SN - 0928-0707 SN - 1573-4846 VL - 62 IS - 3 SP - 273 EP - 280 PB - Kluwer Academic Publ. CY - Dordrecht AN - OPUS4-27617 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hmood, F. J. A1 - Wilbig, Janka A1 - Nicolaides, Dagmar A1 - Zocca, Andrea A1 - Günster, Jens T1 - An approach to monitor the real-time deformation during heat treatment of 3D-printed glass N2 - This study suggests a tool for a better control on the sintering/crystallization of 3D-printed bioactive glassceramics bodies. A small cantilever in form of a bar with square cross section attached to a base and inclined 34◦ with the horizon, was used to monitor the viscous flow and sintering/crystallization headway of a glassceramic systems. 3D printing and sintering of bioactive glass-ceramics is of great interest for medical care applications. Viscous flow ensures sufficient densification of the typically low density printed green bodies, while crystallization prevents the structure from collapsing under the gravitational load. As a model system, a bioactive glass called BP1 (48.4 SiO2, 1 B2O3, 2 P2O5, 36.6 CaO, 6.6 K2O, 5.6 Na2O (mol%)), which has a chemical composition based on that of ICIE16, was employed in this work. In addition, ICIE16 was used as a reference glass. The results show that the suggested design is a very promising tool to track the real-time deformation of 3D printed glass-ceramic specimens and gives a good indication for the onset of crystallization as well. KW - Real-time deformation KW - Sintering KW - 3D-printing KW - Bioactive glass PY - 2021 U6 - https://doi.org/10.1016/j.ceramint.2021.03.334 VL - 47 IS - 14 SP - 20045 EP - 20050 PB - Elsevier Ltd. AN - OPUS4-53449 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mühler, T. A1 - Wirth, Cynthia A1 - Ascheri, Mary A1 - Nicolaides, Dagmar A1 - Heinrich, J. A1 - Günster, Jens T1 - Slurry-based powder beds for the selective laser sintering of silicate ceramics N2 - Selective laser sintering of ceramic powders is a promising technique for the additive manufacturing of complex- and delicate-shaped ceramic parts. Most techniques have in common that the powder to be sintered is spread to a thin layer as a dry powder by means of a roller or shaker system. These layers have a relatively low density. On the other hand, appreciable densities can be reached with the use of ceramic slurries as the starting material. Therefore, the layer-wise slurry deposition (LSD) process has been developed. Layer stacks, i.e. powder beds, built up by employing the LSD technology exhibit a density comparable to ceramic powder compacts processed by means of conventional forming technologies. Writing the layer information with a focused laser beam in these dense ceramic powder compacts enables the manufacture of ceramic bodies with a high density and precision in contour. KW - Additive Fertigung KW - Keramik PY - 2015 U6 - https://doi.org/10.4416/JCST2015-0007 SN - 2190-9385 VL - 6 IS - 2 SP - 113 EP - 118 PB - Göller CY - Baden-Baden AN - OPUS4-34962 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Orlov, Nikolai A1 - Milkin, P. A1 - Evdokimov, P A1 - Putlayev, V. A1 - Günster, Jens A1 - Nicolaides, Dagmar T1 - Bioceramics from Ca3(PO4)2 - CaKPO4 - CaNaPO4 system for bone replacement and grafting N2 - Biomaterials for bone replacement and grafting should possess sufficient strength, be bioresorbable and demonstrate osteoconductivity/osteoinductivity. Nowadays, hydroxyapatite (HA) and tricalcium phosphate (TCP) are the most widespread ceramics for bone grafting at the market, however, their resorption is reported, in some cases, to be not enough. This is why the search for more soluble ceramics compared to HA and TCP looks rather viable. A possible way to increase ceramics solubility leads to partial substitution of Ca2+-ions in Ca3(PO4)2 by alkali castions, like Na+ or/and K+. Improvement of solubility stems from decreasing lattice energy of a substituted phase, as well as increase in hydration energy of the ions releasing from the phase to ambient solution. From this viewpoint, bioceramics based on compositions from Ca3(PO4)2 - CaKPO4 - CaNaPO4 ternary system seems to be prospective for bone replacement and grafting in sense of resorption properties. At the same time, one should bear in mind that solubility level (resorbability) is governed not only by reduction of lattice energy, but also by microstructure features. Grain sizes and porosity contribute much to dissolution rate making study of sintering of aforementioned ceramics highly important. T2 - Biomaterials and Novel Technologies for Healthcare, 2nd International Biennial Conference BioMaH CY - Frascati (Rome), Italy DA - 08.10.2018 KW - Bio Ceramics KW - Bioresorbable PY - 2018 AN - OPUS4-46035 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -