TY - CONF A1 - Kang, M. A1 - Czasny, M. A1 - Kober, D. A1 - Reschetnikow, A. A1 - Stargardt, Patrick A1 - Mieller, Björn A1 - Gurlo, A. T1 - Influence of mica particle content in composites for high voltage applications produced by additive manufacturing and mold casting N2 - The insulation system of high voltage electrical devices like generators and electrical motors has to withstand thermal, electrical, ambient and mechanical influences (TEAM) during operation. Especially the dielectric properties have to satisfy the requirements also under elevated temperatures and extreme environments. To provide this high quality, the conventional fabrication process uses partly manually applied insulation tapes combined with a cost-intensive and under safety concerns at least problematic vacuum pressure impregnation step (VPI). In order to reduce process costs by increasing the degree of automation and avoiding the VPI process, additively manufactured (AM) insulations were studied. This study focuses on the fabrication of ceramic/polymer compounds via AM technique. The AM technology used a rotating screw extrusion print head with air pressure to supply the paste. Plate-like samples with dimensions of 55 mm x 55 mm x1mm thickness were produced. This work focuses on the homogeneously high viscous paste with 12.5 to 50 volume % ratio of filler particles. Three types of mica powders as ceramic filler materials with different particle sizes from micro to mm scale were evaluated. The controlled volume % ratio of particles affects the paste viscosity which enables stacking of paste layers with a viscosity close to clay pastes. The mixed pastes were cured by heating and UV light to increase mechanical properties. A TG/DTA was performed, and electrical properties were investigated. First experiments with respect to the dielectric properties such as volume resistance, permittivity and dielectric strength revealed promising results and the possibility to use AM techniques for the fabrication of high voltage insulations for electrical machines. T2 - MaterialsWeek 2021 CY - Online meeting DA - 07.09.2021 KW - HV-Insulation KW - Polymer-Ceramic-Composite KW - Additive manufacturing PY - 2021 AN - OPUS4-54368 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Westwood, S. A1 - Josephs, R. A1 - Daireaux, A. A1 - Wielgosz, R. A1 - Davies, S. A1 - Wang, H. A1 - Rodrigues, J. A1 - Wollinger, W. A1 - Windust, A. A1 - Kang, M. A1 - Fuhai, S. A1 - Philipp, Rosemarie A1 - Kuhlich, Paul A1 - Wong, S.-K. A1 - Shimizu, Y. A1 - Pérez, M. A1 - Avila, M. A1 - Fernandes-Whaley, M. A1 - Prevoo, D. A1 - de Vos, J. A1 - Visser, R. A1 - Archer, M. A1 - LeGoff, T. A1 - Wood, S. A1 - Bearden, D. A1 - Bedner, M. A1 - Boroujerdi, A. A1 - Duewer, D. A1 - Hancock, D. A1 - Lang, B. A1 - Porter, B. A1 - Schantz, M. A1 - Sieber, J. A1 - White, E. A1 - Wise, S. A. T1 - Final report on key comparison CCQM-K55.a (estradiol): an international comparison of mass fraction purity assignment of estradiol N2 - Under the auspices of the Organic Analysis Working Group (OAWG) of the Comité Consultatif pour la Quantité de Matière (CCQM) a key comparison, CCQM K55.a, was coordinated by the Bureau International des Poids et Mesures (BIPM) in 2009/2010. Eleven national measurement institutes and the BIPM participated. Participants were required to assign the mass fraction of estradiol present as the main component in the comparison sample (CCQM-K55.a) which consisted of a bulk estradiol hemihydrate material obtained from a commercial supplier that had been extensively but not exhaustively dried prior to sub-division into the units supplied for the comparison. Estradiol was selected to be representative of the performance of a laboratory's measurement capability for the purity assignment of organic compounds of medium structural complexity [molar mass range 300–500 Da] and low polarity (pKOW < -2) for which related structure impurities can be quantified by capillary gas phase chromatography (GC) or by high performance liquid chromatography (LC). The majority of participants used a mass balance approach to determine the estradiol content. The key comparison reference value (KCRV) for estradiol in CCQM-K55.a was assigned by combination of KCRVs assigned by consensus from participant results for each orthogonal impurity class. This allowed participants to demonstrate the efficacy (or otherwise) of their implementation of the mass balance approach and to demonstrate that their assigned value for the main component agreed with the KCRV through use of internally consistent contributing methods. The KCRV for the estradiol content of the material was 984.3 mg/g with a combined standard uncertainty of 0.42 mg/g. The individual participant results showed that a relative expanded uncertainty for the purity assignment of 0.2% is a reasonable estimate of the best achievable result by an individual laboratory for a material of this complexity available in this amount at this level of purity. The relative expanded uncertainties reported by laboratories having results consistent with the KCRV ranged from 0.2% to 0.8%. The review of results that were biased from the KCRV showed that two major analytical challenges are posed by the material: the measurement of its water content and controlling for related substance artefact formation during the analysis process. The results displaying a positive bias relative to the KCRV (overestimation of estradiol content) were due to underestimation of the water content of the material, while those with a negative bias (underestimation of estradiol) overestimated the total related substance impurities through a failure to detect and control for artefact formation arising from in situ oxidative dimerization of estradiol in neutral solution prior to analysis. There was however good agreement between all participants in the identification and the quantification of the individual related structure impurities actually present in the sample. The comparison also demonstrated the utility of high-field 1H NMR for both quantitative and qualitative analysis of high purity compounds. It is noted that all the participants who used qNMR as a major or contributing technique and included it as part of, combined it or confirmed it with a conventional 'mass balance' data estimate, obtained results consistent with the KCRV. PY - 2012 U6 - https://doi.org/10.1088/0026-1394/49/1A/08009 SN - 0026-1394 SN - 1681-7575 VL - 49 IS - 1A Tech. Suppl. / 08009 SP - 1 EP - 33 PB - Inst. of Physics Publ. CY - Bristol AN - OPUS4-26411 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Westwood, S. A1 - Josephs, R. A1 - Daireaux, A. A1 - Wielgosz, R. A1 - Davies, S. A1 - Kang, M. A1 - Ting, H. A1 - Philipp, Rosemarie A1 - Malz, Frank A1 - Shimizu, Y. A1 - Frias, E. A1 - Pérez, M. A1 - Apps, P. A1 - Fernandes-Whaley, M. A1 - De Vos, B. A1 - Wiagnon, K. A1 - Ruangrittinon, N. A1 - Wood, S. A1 - Duewer, D.L. A1 - Schantz, M.M. A1 - Bedner, M. A1 - Hancock, D. A1 - Esker, J. T1 - An international comparison of mass fraction purity assignment of theophylline: CCQM pilot study CCQM-P20.e (Theophylline) PY - 2009 U6 - https://doi.org/10.1088/0026-1394/46/1A/08019 SN - 0026-1394 SN - 1681-7575 VL - 46 IS - 08019 SP - 1 EP - 37 PB - Inst. of Physics Publ. CY - Bristol AN - OPUS4-20030 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -