Einfluss der Temperbedingungen auf das Kristallisationsverhalten hocheisenhaltiger Gläser. - In: Programm und Referate, ISBN 978-3-921089-55-2, (2008), insges. 8 S.
Application of micro structured photosensitive glass for the gravure printing process. - In: Microsystem technologies, ISSN 1432-1858, Bd. 14 (2008), 9/11, S. 1635-1639
http://dx.doi.org/10.1007/s00542-008-0602-7
High aspect ratio glass structures produced by means of the drawing technology. - In: Microsystem technologies, ISSN 1432-1858, Bd. 14 (2008), 9/11, S. 1541-1544
http://dx.doi.org/10.1007/s00542-008-0562-y
The contribution of radiation heat transfer in temperature distribution of EM driven semi-transparent glass melt flow. - In: Proceedings of the 7th International Pamir Conference Fundamental and Applied MHD and COST P17 Annual Workshop 2008, (2008), S. 191-195
Modelling the temperature homogeneity of the glass melt obtained by EM action. - In: Przeglad elektrotechniczny, ISSN 0033-2097, Bd. 84 (2008), 11, S. 165-169
Mathematical model of semi-transparent melt flow, which is caused by thermal and EM convection, has been developed. Impact of thermal boundary conditions and absorption coefficient on the temperature distribution of the melt has been analysed numerically. It has been shown that convective and radiative heat transfer influence meltâs temperature distribution significantly and can both: increase or decrease temperature homogeneity of the melt.
Farbe und "Nichts" : Themen der aktuellen Glasforschung: Löcher bestimmen die Funktion optischer Systeme. - In: Rot, grün, blau, (2008), S. 130-133
Potenziale elektromagnetischer Kräfte zur Modifizierung von Glasschmelzen. - In: Programm und Referate, ISBN 978-3-921089-55-2, (2008), insges. 16 S.
Die elektromagnetische Modifizierung von Materialien mittels elektromagnetisch generierter Kraftdichten steht seit Jahren im Fokus wissenschaftlicher Untersuchungen. Dazu zählen Prozesse wie das Schmelzen, Erstarren, Kristallisieren, Abscheiden von metallischen und anorganisch-nichtmetallischen Materialien in Magnetfeldern. - Grundsätzliche Voraussetzungen für die Wirkung von elektromagnetischen Kräften in Materialien sind bewegliche elektrisch geladene Teilchen (woraus elektrische Leitfähigkeiten resultieren, mit denen in einem elektrischen Feld Stromdichten erzeugt werden können) oder bewegliche mit magnetischen Momenten behaftete Teilchen/Bereiche (woraus endliche Suszeptibilitäten resultieren) und in jedem Fall das Vorhandensein eines Magnetfeldes. Dann wirken im oder auf das Material Lorentzkräfte und/oder paramagnetische Kräfte. - Im vorliegenden Beitrag werden die Realisierbarkeit solcher elektromagnetischer Kräfte in Glasschmelzen diskutiert und Ergebnisse zu deren Modifizierung aus eigenen Forschungen, die im Rahmen der von der DFG seit 2001 geförderten Forschergruppe "Magnetofluiddynamik" und weiterer bilateraler FuE-Projekte durchgeführt werden konnten, vorgestellt.
Synthesis of partial Mn2+/Ti4+-substituted single crystalline barium hexaferrite powders by glass crystallization technique. - In: Proceedings of the 10th international conference of the European Ceramic Society (ECerS), (2008), S. 803-808
Single crystalline hexaferrite powders with tailor-made properties are again interesting for different innovative applications, e.g. high-density recording media, chemical and microwave absorbing materials or hyperthermia in medicine. For the preparation of modified single crystalline barium hexaferrite powders (BaFe12-2xAIIxBIVxO19) we used the glass crystallization technique in the system BaO-Fe2O3-B2O3. The modifications result from the variation of the crystallization conditions and the partial substitution of the Fe3+-ions by Mn2+- and Ti4+-ions. - We report modifications of the crystallization behaviour, the phases, morphology and the magnetic properties of the barium hexaferrite powders. The crystallization behaviour was investigated by differential scanning calorimetry. The phases were determined by X-ray diffraction. The crystal morphology was analysed by scanning electron microscopy. The magnetic properties were measured by a vibrating sample magnetometer. Further the chemical compositions were determined by different methods, for example ICP. - The investigations show that increasing Fe3+-ion substitution causes decreasing coercivities at nearly constant saturation magnetizations without the change of the crystallographic structure (M-type). The attained cation substitutions Mn2+/Ti4+ in the hexaferrite crystals increase up to 2x = 3 with increased melt dopings MnO/TiO2 up to 10.8 mole-% . The partial Fe3+-substitutions in the powder are predetermited by the melt dopings. The properties are compared to undoped barium hexaferrite powders and to the results of other works.
Modelling of EM glass convection. - In: Compel, ISSN 2054-5606, Bd. 27 (2008), 2, S. 387-398
An application of external magnetic field to intensify the stirring process of electro-conducting melts is a well-known industrial method. In that case melt flows not only due to the temperature differences caused by thermal boundary conditions (BC) and Joule heat production but also due to a contribution of the Lorentz force. In our case the character of opaque weakly conducting glass melt flow with temperature - dependent physical properties has been investigated. Homogeneity of temperature is one of the pre-requisites for the high quality of the special glasses. The impact of the interaction between the external homogeneous magnetic field and the electrical current flowing in the melt on the melt flow has been analysed experimentally in a laboratory crucible system. The measurements of total Joule heat production rate and the corresponding vertical temperature are used as the essential information for verification of the presented mathematical model. Simulations show EM-field, HD and temperature distribution in 3D geometry of the melt. ANSYS software is used for numerical modelling of coupled EM, hydrodynamics and heat transfer processes. A good qualitative agreement between the numerical and experimental data has been obtained. Numerical proof has been derived that non-inductive approximation is appropriate for the conditions of the experiment. Multiple choices of thermal boundary conditions are discussed and its impact on the total heat balance and temperature distribution in the melt.
http://dx.doi.org/10.1108/03321640810847670
Damage tolerant, translucent oxide fiber/glass matrix composites. - In: Composites, ISSN 1879-1069, Bd. 39 (2008), 2, S. 362-373
http://dx.doi.org/10.1016/j.compositesb.2007.01.002