Effect of temperature on the microwave absorption characteristics of C/PIP-SiC composite materials

The growing sophistication of radar detection technology necessitates the development of high-performance, high-temperature stealth materials. This study employed the Polymer Infiltration and Pyrolysis (PIP) method to fabricate C/PIP-SiC composites and comparatively analyzed the effect of different air oxidation temperatures on their microwave absorption performance across the 1.00–18.00 GHz range. The results highlight significant performance changes corresponding to the thermal treatment. The unoxidized sample (S0) showed weak absorption, with a minimum reflection loss (RL_min) of − 9.28 dB. Similarly, the sample treated at 900 °C (S1) showed no considerable improvement. A dramatic enhancement was observed when the oxidation temperature was raised to 1200 °C (S2), which exhibited an exceptional RL_min of − 46.56 dB at a thickness of 2.20 mm and a frequency of 16.30 GHz. This optimal performance is a result of enhanced dielectric loss and superior impedance matching, facilitated by the formation of surface defects and heterogeneous interfaces. Conversely, treatment at 1500 °C (S3) resulted in structural damage and a sharp decline in absorption capability, failing to achieve effective absorption. This work demonstrates that oxidation at 1200 °C is the optimal condition for C/PIP-SiC, enabling the precise tuning of its electromagnetic properties for advanced applications.