FARADAYIC PROCESS FOR ELECTROPHORETIC DEPOSITION OF THERMAL BARRIER COATINGS

Faraday is pursuing the development of an electrically mediated process for electrophoretic deposition (EPD) of thermal barrier coatings (TBCs), termed the Faradayic EPD Process. This process will be capable of depositing coating materials that enable higher temperatures in natural gas and synthesis gas environments while maintaining the necessary durability and reliability required to sustain the engine life expectancy. This process will alleviate issues associated with other deposition methods, such as DC EPD, which can have poor throwing power due to non-uniform current distributions, poor utilization of powder and increased cost. This electrically mediated process utilizes an asymmetric electric field to control the uniformity, deposition rate and material properties of a ceramic coating. Prior work used the Faradayic EPD process to apply thermal barrier coatings onto Inconel 718 substrates. Experimental studies showed that the Faradayic EPD process could a) uniformly deposit YSZ thermal barrier materials and b) increase deposition rates of thermal barrier materials compared with more conventional processes. In current work, Faraday is optimizing and validating the Faradayic EPD process for thermal barrier coatings to prevent coating failure during standard and accelerated turbine engine operation. This includes the development and validation of deposition related parameters to ensure a suitable coating, post deposition thermal treatments to preserve the necessary microstructure to maintain coating durability and reliability during operation, and the selection of appropriate tests of merit to qualify the coating durability and reliability.