La0.5Sr0.5FeO3-YSZ based coating for high-temperature microwave absorption and thermal insulation up to 1000 ℃

To address the urgent need for integrated thermal-electromagnetic protection in hypersonic vehicle hot-end components, this study combines the wave-absorbing material La 0.5 Sr 0.5 FeO 3 (LSF) with the thermal insulation material Y 2 O 3 -stabilized ZrO 2 (YSZ) to prepare LSF-YSZ-based high-temperature functional coatings (referred to as LSFZ coatings) via atmospheric plasma spraying (APS). At 1000 °C, a 1.3 mm-thick coating achieved full X-band RL ≤ −4 dB, with thermal conductivity as low as 1.2 W/(m·K), and produced a temperature drop of 303 °C. Further analysis reveals the formation of a multiphase composite porous nanostructure in the coating. The electromagnetic loss mechanism gradually shifted from polarization loss to conductivity loss dominance as temperature increased. This study provides new insights for the design of thermal/electromagnetic synergistic protective coating under extreme environments.