Embedded Sensors in Turbine Systems by Direct Write Thermal Spray Technology

70364B02-II Monitoring the performance of high temperature components in advanced gas turbine engines will be required in order to accelerate the insertion of advanced materials, coatings, and novel designs. For example, by continuously collecting component temperature and strain information, one can provide feedback on the efficiency and performance of the engine as well as the health of engineering components. Embedded sensors could achieve this requirement; however, the incorporation of sensors within harsh turbine environments represents a challenging task. In this project, embedded sensors will be incorporated within thermal and environmental barrier coatings through a newly developed conformal direct write thermal spraying process for thick film sensors, providing an innovative means to integrate robust, reproducible, thermocouples and strain sensors onto engine components. Phase I demonstrated that E and K-type thermocouples could be fabricated and incorporated within yttria stabilized zirconia thermal barrier coatings. The sensors measured temperatures up to 1200oC within the coating and survived prolonged exposure in a furnace and burner rig environment. Phase II will identify key components in turbine engines that are suitable for using this technology for condition monitoring. The sensor design, location, layout, lead wire extraction and signal collection issues will be iteratively optimized. The sensors will be fabricated and tested in bare and embedded mode with varying thicknesses of the protective coatings. Sensor performance will be assessed with respect to design criteria, survivability and behavior of the integrated component/coating. Commercial Applications and Other Benefits as described by awardee: The in situ condition monitoring of gas turbine engines should be of major benefit to the energy sector since it enables performance optimization, failure assessment, and the condition-based maintenance of components (particularly coatings). The technology not only should be applicable to the gas turbine industry, but also could be easily extended to other harsh environment situations such as in fossil fuel power plants, diesel engines, and marine and space propulsion systems. Other applications include automotive, aeronautical, marine, and diesel engines.