@article{LI2021, 
author = {Junsheng LI and Qiuping YU and Duan LI and Liang ZENG and Shitao GAO},
title = {Formation of hierarchical Si3N4 foams by protein-based gelcasting and chemical vapor infiltration},
year = {2021},
journal = {Journal of Advanced Ceramics},
volume = {10},
number = {1},
pages = {187-193},
keywords = {ceramics, sintering, porosity, mechanical properties, permeability},
url = {https://www.sciopen.com/article/10.1007/s40145-020-0431-4},
doi = {10.1007/s40145-020-0431-4},
abstract = {Silicon nitride foams with a hierarchical porous structure was formed by the combination of protein-based gelcasting, chemical vapor infiltration, and in-situ growth of silicon nitride nanowires. The porosity of the foams can be controlled at 76.3-83.8 vol% with an open porosity of 70.2-82.8 vol%. The pore size distribution was presented in three levels: < 2 μm (voids among grains and cross overlapping of silicon nitride nanowires (SNNWs)), 10-50 μm (cell windows), and >100 μm (cells). The resulted compressive strength of the porous bodies at room temperature can achieve up to 18.0±1.0 MPa (porosity = 76.3 vol%) while the corresponding retention rate at 800 ℃ was 58.3%. Gas permeability value was measured to be 5.16 (cm3·cm)/(cm2·s·kPa). The good strength, high permeability together with the pore structure in multiple scales enabled the foam materials for microparticle infiltration applications.}
}