Abstract
Ceramic matrix composites (CMCs) are promising materials for high-temperature applications. Environmental barrier coatings (EBCs) are needed to protect the components against water vapor attack. A new potential EBC material, YAlO3, was studied in this paper. Different plasma-spraying techniques were used for the production of coatings on an alumina-based CMC, such as atmospheric plasma spraying (APS) and very low pressure plasma spraying (VLPPS). No bond coats or surface treatments were applied. The performance was tested by pull–adhesion tests, burner rig tests, and calcium-magnesium-aluminum-silicate (CMAS) corrosion tests. The samples were subsequently analyzed by means of X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectroscopy. Special attention was paid to the interaction at the interface between coating and substrate. The results show that fully crystalline and good adherent YAlO3 coatings can be produced without further substrate preparation such as surface pretreatment or bond coat application. The formation of a thin reaction layer between coating and substrate seems to promote adhesion.
Highlights
The efficiency of a gas turbine is determined by its pressure ratio and its maximum service temperature
The coating performance was tested with burner rig tests, and the results suggested a strong dependence of adhesion on the used Ceramic matrix composites (CMCs) material
Plasma-sprayed YAlO3 coatings as Environmental barrier coatings (EBCs) for an Al2 O3 -based CMC will be discussed in this study, paying special attention to the phase evolution during plasma spraying
Summary
The efficiency of a gas turbine is determined by its pressure ratio and its maximum service temperature. Reinforcing of the ceramic matrix with ceramic fibers avoids catastrophic failure due to crack deflection and bridging mechanisms and leads to a pseudo-plastic failure behavior of the ceramic material [3] These so-called ceramic matrix composites (CMCs) combine high chemical and thermal stability with moderate creep rates and high strength. Compared to SiC, Al2 O3 offers higher resistance against oxidation and corrosion [3] For this reason, an alumina-based CMC was chosen in this study. EBCshould shouldhave haveaahigh highresistance resistance against water vapor at elevated temperatures; corrosion rates of many materials were studied in the past Large CTE differences between substrate and EBC cause heating cooling and and maycooling lead to and premature failure.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
