Enhanced high‐temperature dielectric and microwave absorption properties of SiC fiber‐reinforced oxide matrix composites

Abstract

Because of outstanding performances of the SiC fiber‐reinforced ceramic matrix composites in aircraft/aerospace systems, two silicon carbide fiber‐reinforced oxide matrices (SiCf/oxides) composites have been prepared by a precursor infiltration and sintering method. Results indicate that the flexural strength of the SiCf/Al2O3–SiO2 composite reaches 159 MPa, whereas that of the SiCf/Al2O3 composite is only 50 MPa. The high‐temperature microwave absorption properties of the composite are significantly enhanced due to choosing Al2O3 and SiO2 as the hybrid matrices. Particularly, the minimum reflection loss (RL) value of the SiCf/Al2O3–SiO2 composite reaches −37 dB in the temperature of 200 °C at 8.6 GHz, and the effective absorption bandwidth (RL ≤ −5 dB) is 4.2 GHz (8.2–12.4 GHz) below 400 °C. The superior microwave absorption properties at high temperatures indicate that the SiCf/Al2O3–SiO2 composite has promising applications in civil and military areas. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47097.

High-Temperature Dielectric and Microwave Absorption Property of Atmospheric Plasma Sprayed Al2O3-MoSi2-Cu Composite Coating

“…With the increase in temperature, the dielectric constant of the coating increases, and the absorbing bandwidth of the coating moves from high frequency to low frequency. This law conforms to Formula (12) [32].…”

Rational Design of a Core–Shelled Ti3AlC2@La2Zr2O7 Composite for High-Temperature Broadband Microwave Absorption

“…In the range of the X band, the EAB of the core–shelled TAC@LZO structure at room temperature is 4 GHz (2.57 mm), which exceeds those of most MAX phase related absorbers reported in the literature (Figure g and Table S3). − ,,− In comparison to the high-temperature MAMs with antioxidant resistance materials − (Figure h), whose EABs vary in the temperature range below 600 °C, the core–shelled TAC@LZO composite exhibits a stable EAB bandwidth at 25–600 °C. This result further indicates the advantages of TAC@LZO as an efficient and stable wide-temperature-range MAM.…”

High temperature microwave absorbing materials

“…Gao et al prepared SiC f /Al 2 O 3 –SiO 2 composites via the precursor infiltration and sintering method. 51 The pyrolysis process will weaken the mechanical properties of the ceramic owing to the volume shrinkage and growth of pores. The introduction of oxide ceramics can offset the disadvantage and improve the ceramic oxidation resistance.…”