Single source precursor derived SiBCNHf ceramic with enhanced high‐temperature microwave absorption and antioxidation

• Published in: Journal of materials science & technology 2022-11, Vol.126, p.215-227
• Main Authors: Song, Yan, Liu, Ziyu, Zhang, Xicheng, Zhu, Runqiu, Zhang, Youwei, Liu, Pinggui, He, Lihua, Kong, Jie
• Format: Article
• Language: English
• Subjects: Antioxidation performance; EM wave absorption; hb-PBSZ-Hf precursor; SiBCNHf ceramic
• ISSN: 1005-0302; 1941-1162
• DOI: 10.1016/j.jmst.2022.03.015

•A hafnium-containing hyperbranched polyborosilazane (hb–PBSZ–Hf) precursor was prepared and pyrolyzed to obtain SiBCNHf ceramic.•HfC, SiC, HfB2 nanocrystals and free carbons nanophase were in situ generated in SiBCNHf ceramic after annealing at high temperature.•The SiBCNHf ceramics with particular high-temperature and antioxidation performance possess excellent EM wave-absorbing properties in high-temperature and harsh environments. Electromagnetic (EM) wave-absorbing materials with high-temperature-resistance are urgently desirable to eliminate EM interference in extreme conditions. Precursor derived ceramics (PDC) route is being evolved as an effective strategy to solve the puzzle. Herein, a single source hyperbranched polyborosilazane precursor containing hafnium (hb-PBSZ-Hf) is introduced and the SiBCNHf ceramic is obtained by further pyrolysis. The micro-sized tissues including HfC, SiC, HfB2 nanocrystals and segregated carbons are in situ generated during annealing which not only increase EM wave absorption ability (minimum reflection coefficient (RCmin) is -56.71 dB with a thickness of 2.5 mm, effective absorption bandwidth (EAB) is 3.4 GHz), but also improve antioxidation property (less than 2 wt.% mass fluctuation at 1400 °C in air). Theoretical simulation of complex permittivity suggests that SiBCNHf ceramic has an RCmin of less than -5 dB for the whole X-band even at 1100 °C. Such SiBCNHf ceramic with superior high-temperature-resistance and antioxidation performance derived from single source precursors possesses great potential for EM wave absorbing coatings in high-temperature and harsh environments.