TY - GEN A1 - Mieller, Björn T1 - Pressure-assisted sintering of Ca3Co4O9 multilayers for thermoelectric applications N2 - The development of competitive thermoelectric generators using oxide ceramics and multilayer technology requires the investigation of suitable sintering procedures. The sintering of Ca3Co4O9, which is the most promising p-type oxide regarding its figure of merit, is a special challenge, as the material starts to decompose at 926 °C. Pressure-assisted sintering (PAS), as known from large-scale production of low temperature co-fired ceramics, was used to sinter multilayers of Ca3Co4O9 green tape at 900 °C with different pressures and dwell times. In-situ shrinkage measurements, microstructural investigations and electric measurements were performed. Relative density increases from 57.4 % after free sintering for 24 h to 93.7 % after 2 h of PAS with 10 MPa axial load. The combination of tape casting and PAS induces a pronounced alignment of the anisotropic grains. In comparison to freely sintered multilayers, the electrical conductivity in the casting direction is thereby strongly increased by a factor of 5. With respect to dry-pressed bars, the improvement amounts to a factor of 15. This study shows that PAS is a proper technique to produce dense Ca3Co4O9 panels with good thermoelectric properties similar to hot-pressed tablets, even in large-scale production. T2 - International Conference on Sintering 2017 CY - San Diego, USA DA - 12.11.2017 KW - Thermoelectric oxide KW - Multilayer KW - Sintering KW - Calcium cobaltite PY - 2017 UR - https://opus4.kobv.de/opus4-bam/frontdoor/index/index/docId/42975 AN - OPUS4-42975 AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany