@article{DING2022, 
author = {Donghai DING and Runan LI and Li ZHANG and Kai PENG and Guoqing XIAO and Feng DUAN and Peilin DENG and Jie LI},
title = {Effect of Heat-Treatment Temperature on Properties of SiO2f/SiO2 Composites},
year = {2022},
journal = {Journal of the Chinese Ceramic Society},
volume = {50},
number = {7},
pages = {2005-2014},
keywords = {precursor impregnation heat treatment method, quartz fiber, silica matrix ceramics, composites, thermal insulation, mechanical property},
url = {https://www.sciopen.com/article/10.14062/j.issn.0454-5648.20210830},
doi = {10.14062/j.issn.0454-5648.20210830},
abstract = {It is of great practical significance to develop thermal insulation materials with integrated load bearing and thermal insulation for energy saving and emission reduction in high-temperature engineering. In this work, SiO2f/SiO2 composites were prepared by a precursor impregnation heat-treatment method with quartz fiber needled felt as a reinforcement and silica sol as a precursor. The effect of heat-treatment temperature on the density, porosity, mechanical properties and thermal properties of SiO2f/SiO2 composites was investigated. The composition and microstructure of the composites were characterized by X-ray diffraction and scanning electron microscopy. The coefficient of thermal expansion and thermal conductivity of composites were measured by a push rod method and a transient hot-wire method. The results indicate that the apparent porosity and mechanical strength firstly increase and then decrease with the increase of heat-treatment temperature. The sample after heat-treatment at 450 ℃ has the optimum overall performance (i.e., the flexural strength of 23.5 MPa, and the compressive strength of 61.9 MPa). The fracture mechanism is a ductile fracture. At 300–700 ℃, the thermal expansion coefficient of the sample is 0.564×10-6/℃. The thermal conductivity of the samples decreases with the increase of temperature, and it is as low as 0.096 W/m·K at 700 ℃. The SiO2f/SiO2 composite prepared has some advantages in the integrated application of load bearing and thermal insulation, and meets the harsh requirements of hot pressing and sintering, non-ferrous metallurgy and other industries.}
}