posted on 2023-11-01, 10:08authored byXuan Zhang, Jianyong Yu, Cunyi Zhao, Yang Si
SiC is an exceptionally competitive material for porous
ceramics
owing to its excellent high-temperature mechanical stability. However,
SiC porous ceramics suffer from serious structural damage and mechanical
degradation under thermal shock due to the hard SiC microstructure
and weak bonding networks. Here, we report a scalable interface-engineering
protocol to reliably assemble flexible amorphous SiC nanofibers into
lamellar cellular meta-aerogels by designing a covalent heterointerface.
This approach allows the construction of a strong binding architecture
within the resilient nanofiber skeleton network, thereby achieving
structurally stable, mechanically robust, and durable SiC porous ceramics.
The optimized amorphous SiC meta-aerogels (a-SiC MAs) exhibit the
integrated properties of ultralight with a density of 4.84 mg cm–3, temperature-invariant superelastic, fatigue-resistant
at low 5% permanent deformation after 1000 cycles of compression,
and ultralow thermal conductivity (19 mW m–1 K–1). These characteristics provide a-SiC MAs potential
application value in the thermal protection field.