Here is the abstract you requested from the hiten_2019 technical program page. This is the original abstract submitted by the author. Any changes to the technical content of the final manuscript published by IMAPS or the presentation that is given during the event is done by the author, not IMAPS.
|On-turbine multisensors based on hybrid ceramic manufacturing technology|
|Keywords: Sensor, Turbine, Mulitlayer Ceramics|
|Robust and reliable sensors are essential for condition monitoring and for development of jet engines and turbines. They offer to optimize control mechanisms, improve energy efficiency, reduce exhaust emissions, increase service intervals and refine lifetime prediction and process understanding. On-turbine sensors underlie harsh environmental conditions including high temperatures and temperature cycles, aggressive media, demanding vibrational stress, increased humidity and wear by salt or dust particles. Established solutions consist of miniaturized, hermetically packaged SOI sensory elements  or quartz based piezoelectric solutions . The intention of the development is to evaluate the potential of piezoresistive multilayer ceramic sensory solutions using Low or High Temperature Cofired Ceramics (LTCC/HTCC) . Based on a user defined catalogue of requirements a sensor concept consisting of sensory element, signal conditioning electronics, packaging resp. interconnects and housing was worked out. Relevant ceramic materials were characterized and evaluated with regard to applicability and reliability under application conditions. Based on the preliminary investigations sensor designs were prepared, test samples manufactured and ceramic compatible packaging solutions investigated. These samples were characterized under aspects of functionality and reliability. Further attention was paid to system integration of the ceramic sensory element. The use of robust multisensors with integrated signal conditioning electronics allow for multi-parameter measurement with reduced weight and size, high level output and excellent long term stability. For measuring tasks in turbine environments ceramic materials are highly appropriate. They offer excellent high temperature stability, durability against wear and excellent corrosion stability. Within the investigation several LTCC and HTCC ceramic materials were characterized regarding mechanical properties (bending strength, Youngs modulus, hardness…), thermal properties (thermal expansion, heat conductivity, thermal shock…), electrical properties (resistance, piezoresistive behavior…) and long term stability under increased temperatures. A multilayer ceramic sensory element was designed including a ceramic embedded pressure sensing membrane, a Pt100 temperature sensor and ceramic integrated wiring. Appropriate sealing methods to implement the ceramic into metal housings were worked out as well as electrical connection solutions, which allow for an operation under the increased temperatures (> 300°C) of the application. The sensory element was characterized under application near environmental conditions and evaluated regarding sensory parameters (sensitivity, signal offset, linearity and hysteresis error). Furthermore long time experiments were conducted to evaluate signal drift or component degradation. A system concept including sensory element, signal conditioning electronics, mechanical and electrical interfaces is focus of the further investigation.|
|Steffen Ziesche, Group Leader