1. Improved hot corrosion resistance of plasma sprayed YSZ/Gd2Zr2O7 thermal barrier coating over single layer YSZ
- Author
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Sumil Majithia, S.T. Aruna, P.G. Lashmi, V. Shwetha, and N. Balaji
- Subjects
010302 applied physics ,Materials science ,Mechanical Engineering ,Gadolinium ,Bilayer ,chemistry.chemical_element ,Atmospheric-pressure plasma ,02 engineering and technology ,Penetration (firestop) ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Zirconate ,Corrosion ,Thermal barrier coating ,chemistry ,Mechanics of Materials ,0103 physical sciences ,General Materials Science ,Composite material ,0210 nano-technology ,Yttria-stabilized zirconia - Abstract
In recent years, research is focused on the development of rare earth zirconates based thermal barrier coatings (TBC). In the present study, bilayered 8 wt% yttria stabilized zirconia (YSZ)/gadolinium zirconate (GZO) TBC system has been developed by atmospheric plasma spraying (APS) process from powders prepared by a single step co-precipitation technique. Hot corrosion behavior of all the coatings are tested in fused Na2SO4 + V2O5 mixture at the concentration of approximately 25 mg/cm2 at 910 °C for 30 h. Formation of gadolinium vanadate (GdVO4) is observed to be the corrosion product in YSZ/GZO bilayer coatings from Energy Dispersive X-ray analysis (EDAX) and is further confirmed by X-ray diffractometry (XRD) analysis. FESEM cross-section analysis of the YSZ/GZO bilayer coating after corrosion test affirms the effectiveness of the bilayer design in preventing the penetration of corrosive salts to the YSZ layer. Also, YSZ/GZO bilayer TBC exhibited a higher thermal cyclic life (300 cycles) than the single layer 8YSZ (175 cycles) coatings at 1100 °C.
- Published
- 2019
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