Abstract
Fuel injector tips fabricated from Hastelloy X and Haynes 188 alloys were coated with the electron beam-physical vapor deposition (EB-PVD) MCrAlY overlay coating ATD 63 (Temescal), the platinum aluminide diffusion coatings RT-22A (Chromalloy Research and Technology) and PS 138 (Turbine Metals Technology), an EB-PVD NiCoCrAlY-YSZ overlay coating (Chromalloy Research and Technology) and SN-5A, a vitreous phase ceramic coating (Solar Turbines Incorporated). The coatings were subjected to cyclic oxidation testing at 1149 °C and cyclic corrosion testing with 95%Na 2SO 4-5%NaCl deposits at 982 °C. Gravimetric measurements indicated that the coating stabilities decreased in the order RT-22A 62 SN-5A 62 PS 138 ≈ YSZ (oxidation testing) and YSZ 62 SN-5A 62 RT-22A 62 PS 138 ≈ ATD 63 (corrosion testing). Microstructural examination showed a correlation between oxidation protection and high platinum and aluminum levels for the platinum aluminide diffusion coatings. The NiCoCrAlY-YSZ overlay coating demonstrated poor adherence and spallation in oxidation testing. Debonding of this coating occurred through cracking of the oxidized surface (Al 2O 3) of the bond coat. SN-5A exhibited morphological changes in the coating matrix following oxidation-corrosion testing.
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.
