Structure and mechanical properties of HNTs/SiBCN ceramic hybrid aerogels

Abstract

SiBCN ceramic aerogels have excellent properties such as ultra-high temperature stability, low density and high thermal insulation. The aerogels have better potential applications in aerospace and other fields. However, similar to inorganic aerogels, the low mechanical strength of SiBCN ceramic aerogels are the main limitation of its application. Based on the principle of inorganic double network enhancement, the first network was constructed by PVA and HNTs, and HNTs/SiBCN dual network aerogels were constructed by SiBCN ceramic aerogels as the second network. The structure and mechanical properties were characterized by scanning electron microscope (SEM), transmission electron microscope (TEM), X-ray diffraction (XRD), specific surface area analyzer and pressure tester. Compared with SiBCN ceramic aerogels, 6 wt% HNTs-SiBCN ceramic hybrid aerogels have better microscopic properties (maintaining basic porous network structure and structural stability) and mechanical properties.The continuous HNTs first network can effectively transfer the stress load and enhance the strength of SiBCN ceramic aerogels.