An Improved Deposition Process for Very Thick Porous Thermal Barrier Coatings

Abstract

This paper discusses the development of a two-layer thermal barrier coating that reduces heat flow to the lowest allowable level based on the temperature limits of the materials involved. The thick, porous coating was sprayed using a modified plasma torch and then thermally cycled until failure. Test results show that the process used to apply the bond coat has a measurable effect on the performance of the thermal barrier coatings. In addition to zirconia powders, a low cost polymer powder was used as well. Paper includes a German-language abstract.

Environmental Protection of Metal Structures at High Temperature: State of the Art and Future Trends

“…But in the case where mixing is performed between metals and ceramics, results (for high temperature applications) are generally disappointing because of the rapid oxidation of the dispersed metallic phase [83]. Alternatively, porosity may also be considered as a second phase [74,75], the amount and repartition of which can be adjusted through the deposition process, especially for APS [84].…”