Enhanced microwave absorption properties of polymer-derived SiC/SiCN composite ceramics modified by TiC

Abstract

Porous SiCN(Ti) composite ceramics with good microwave absorbing performance were fabricated by pyrolysis of solid polysilazane modified by tetrabutyl titanate. The introduction of Ti not only acted as active filler to react with free carbon in the matrix to form TiC, but also played the role as catalyst to promote the formation of SiC nanowires. Finally, SiCN(Ti) composite ceramics formed a microstructure containing multi-nanophases and multi-nano heterogeneous interfaces when annealing temperature reached 1500 °C. The complex microstructure annealed at 1500 °C made composite ceramics have good matching impedance, as well as greatly increase the interfacial polarization loss and dipole polarization loss. As a result, the TiC/SiC/SiCN composite ceramics showed the excellent performance of electromagnetic wave absorption in X band. The minimum reflection loss (RL) of samples was − 17.1 dB at the thickness of 1.9 mm, and the maximum effective absorption bandwidth (EAB) of composite ceramics was 3.2 GHz when the thickness of sample was 2.1 mm, which exhibited a promising prospect as a structural and microwave absorbing integration material.

Super‐Wideband Electromagnetic Absorbing TiC/SiOC Ceramic/Glass Composites Derived from Polysiloxane and Titanium Isopropoxide with Low Thickness (<1 mm)

“…Figure 9 summarizes the absorption performance of typical PDCs composites as a function of EAB and sample thickness in the most recent literature. [30,32,[44][45][46][47][48][49][50][51][52][53][54][55][56] It can be seen that in our work, samples at thicknesses of 0.95 and 0.85 mm are capable of achieving %96.3% and %99.94% maximum EMW absorption, respectively. To the best of our knowledge, this is the first time that more than 99.9% EMW absorption has been reported for ceramic materials with a thickness of less than 1 mm, along with a super broad EAB (13.5 GHz), has been reported.…”

“…Absorption rates, effective absorption bandwidth (EAB), and thickness of polymer-derived ceramics from the literature review. [30,32,[44][45][46][47][48][49][50][51][52][53][54][55][56] The unique properties of our presented TiC/SiOC composites demonstrate a significant advantage over other reported EMW absorbing ceramic materials for harsh conditions applications.…”

“…Figure 9. Absorption rates, effective absorption bandwidth (EAB), and thickness of polymer-derived ceramics from the literature review [30,32,[44][45][46][47][48][49][50][51][52][53][54][55][56]. …”

High temperature microwave absorbing materials

“…TiC/SiC/SiCN composites were prepared by a feasible strategy to avoid the agglomeration of fillers. 66 On the one hand, adding Ti as the catalyst into precursors solved the agglomeration of SiC fillers (Fig. 5a and b).…”

Increased microwave absorption property of porous Si3N4 ceramics by loading polymer-derived SiCN for a multifunctional design

“…[12][13][14] Many innovative works have focused on the improvement of the EMW absorption property of PDC-SiCN by controlling the microstructure, adding magnetic or carbon materials, constructing heterogeneous interfaces, etc. [15][16][17][18][19][20][21][22][23][24][25][26][27] In addition, a series of SiCN matrix composites, such as Al 2 O 3f /SiCN, 28 Si 3 N 4 -SiCN, 29 SiCN fiber, [30][31][32] CNWs/ SiC-NWs hybrid network reinforced SiCN, 33 3D printed SiCN honeycomb, 34 and SiCN aerogels 35 have also been fabricated successively and demonstrate excellent EMW absorption properties. In our previous study, 35 an ultralight SiCN ceramic aerogel was produced using a facile method involving hydrosilylation crosslinking, freeze drying, and subsequent high-temperature pyrolysis.…”