Manufacturing of Inconel 718 Based Honeycomb Panels for Metallic Thermal Protection Systems

Abstract:

Metallic thermal protection system (MTPS) offers significant improvements over the ceramic based TPS for reentry applications. Space shuttle refurbishment time is estimated to be around 17000 man hours between flights. Metallic based TPS can be fabricated easily and provides wide range of design options for TPS. Adaptability and robustness of metallic thermal protection systems offers the potential for reusability. In this work, a unique manufacturing process has been evolved to realize light weight honeycomb panels through corrugation, laser welding and diffusion brazing of faceplates, where in 50 micron thick Inconel718 foil is used for making honeycomb core and 0.2mm thick Inconel718 foil as faceplates. The compression and three point bend test on these panels have shown no debond between faceplates and honeycomb core. 150x150x5mm size honeycomb panels were coated with YSZ and NiCrAlY based Thermal Barrier Coatings (TBC) and high temperature tests have shown thermal resistance of around 570 °C with front wall temperature of 1186 °C and back wall of 533 °C. Also these panels have been characterized for reusability by the testing of same panel at different heat flux levels. Though it is found that honeycomb panel has shown its integrity without debond a certain acceptable level of degradation in coating is observed. Thus Inconel718 based honeycomb panels with TBC coating are proved for use as thermal protection system for reusable launch vehicle systems.

• Periodical: Materials Science Forum (Volume 710)
• Pages: 197-202
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.710.197
• Online since: January 2012
• Authors: Hanamantray Baluragi, V. Anil Kumar, K. Narasaiah, Shibu Gopinath, P.P. Sinha
• Keywords: Honeycomb, Inconel 718, MTPS, Reusable Launch Vehicle, Thermal Barrier Coating (TBC)

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