PSI - Issue 60

Sarath Chandran Nair S. et al. / Procedia Structural Integrity 60 (2024) 564–574 Sarath Chandran Nair S./ Structural Integrity Procedia 00 (2023) 000 – 000

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Cylindrical segment (Nickel coating) AFC segment (Nickel coating)

Nozzle first segment (Nickel + Chromium coating)

Fig. 2. Semi-cryogenic engine and coating details

4. Qualification of Thermal Barrier Coating Thermal Barrier coating is developed newly for Semi-cryogenic engine. It is necessary to carry out an elaborate coating qualification tests to ensure that it meets all the functional requirements. Tests simulating the operating condition of tensile and compression loads were also included for coating qualification. Testing of actual hardware will incur cost and time severely. To get confidence and validation of coating before actual hardware testing, specimen level testing will be a suitable method. Hence strain controlled fatigue test method is adopted for TBC qualification. The strain levels for the fatigue tests were arrived at based on a detailed thermo-structural analysis of the combustion/Thrust Chamber. Accordingly, test matrix was formulated for qualification under different conditions. 4.1. Thermo-structural analysis A detailed thermo-structural analysis was carried out for different operating conditions considering temperature distribution and chamber pressure. Temperature of 600C and pressure of 180 bar were considered for analysis. The variation of strains in the cylindrical segment, AFC segment and nozzle first segment are shown in fig. 3.

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b