Lightweight and Strong Ceramic Network with Exceptional Damage Tolerance

Abstract

Lightweight materials such as porous ceramics have attracted increasing attention for applications in energy conservation, aerospace and automobile industries. However, porous ceramics are usually weak and brittle; in particular, tiny defects could cause catastrophic failure, which affects their reliability and limits the potential use greatly. Here we report a SiC/SiO 2 nanowire network constructed from numerous well-bonded SiC nanowires coated by a biphasic structure consisting of amorphous SiO 2 and nanocrystal SiC. The as-obtained SiC/ SiO 2 nanowire network is lightweight (360 ± 10 mg cm −3 ), mechanically strong (compressive strength of 16 MPa), and damage-tolerant. The high strength of the network is attributed to the biphasic mixed structure of the binding coating which can restrict the deformation of nanowires upon compression. The lightweight and strong SiC/SiO 2 nanowire network shows potential for engineering applications in harsh environments.

Engineering the mechanical properties of resilient ceramic aerogels

“…[82][83][84][85] Herein, considering the rapid development and increasing demands for optimization of the mechanical properties of the present resilient ceramic aerogels for various application situations, this paper mainly focuses on the strategies used to improve mechanical properties based on our previous works related to one-dimensional nanostructures-based resilient ceramic aerogels (SiC nanowire aerogels and Si 3 N 4 nanobelt aerogels). 56,59,[86][87][88][89][90][91][92]…”

High-Yield Synthesis of SiC@SiO2 Core–Shell Nanowires on Graphite Substrates for Energy Applications

“…For example, Qu et al prepared SiC@SiO 2 NWs by oxidizing SiC NWs in air at high temperatures (900–1200 °C) and found that SiC@SiO 2 NWs showed better thermal insulation properties than SiC NWs . Lu et al prepared SiC@SiO 2 NWs networks by CVD and subsequent heat treatment at 1200 °C, which have potential for engineering applications in harsh environments owing to their lightweight (360 ± 10 mg cm –3 ), high mechanical strength (compressive strength of 16 MPa), and damage resistance . However, considering the growing global energy demand and the depletion of fossil fuel resources, these methods undoubtedly contribute to increased costs and energy consumption. , …”

“…22 Lu et al prepared SiC@ SiO 2 NWs networks by CVD and subsequent heat treatment at 1200 °C, which have potential for engineering applications in harsh environments owing to their lightweight (360 ± 10 mg cm −3 ), high mechanical strength (compressive strength of 16 MPa), and damage resistance. 23 However, considering the growing global energy demand and the depletion of fossil fuel resources, these methods undoubtedly contribute to increased costs and energy consumption. 24 In contrast, thermal evaporation of Si powders for synthesis of SiC@SiO 2 NWs has advantages of low production cost, a simple process, environmental friendliness, less impurities in the product, and a controllable NWs structure; therefore, this method is conducive to large-scale synthesis.…”

Effect on BN interphase thickness upon SiCnws@BN/HfC coating performance under impact and ablation environment

“…Due to the inherent brittleness, HfC coating cannot meet the service requirements of thermal structural components of aerospace vehicles solely relying on its own thermal protection ability. Aiming at this issue, some scholars proposed that introducing nanowires as reinforcements into ceramic to enhance toughness 25,26 . Ren 27 .…”

“…Aiming at this issue, some scholars proposed that introducing nanowires as reinforcements into ceramic to enhance toughness. 25,26 Ren. 27 introduced HfC nanowires (HfC nws ) into HfC coating, finding that the fracture toughness of the coating was significantly optimized under quasi-static loading.…”