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.

通过基于蛋白质的凝胶浇铸，化学气相渗透和氮化硅纳米线的原位生长相结合，形成了具有分层多孔结构的氮化硅泡沫。泡沫的孔隙率可以控制在76.3-83.8体积％，开放孔隙率为70.2-82.8体积％。孔径分布分为三个级别：<2μm（晶粒间的空隙和氮化硅纳米线（SNNWs）的交叉重叠），10–50μm（孔窗口）和> 100μm（孔）。所得的多孔体在室温下的抗压强度可达到18.0±1.0 MPa（孔隙率= 76.3 vol％），而在800℃下的相应保留率为58.3％。测得的气体渗透率值为5.16（cm ³ ·cm）/（cm ²·s·kPa）。良好的强度，高渗透性以及多种尺度的孔结构使泡沫材料可用于微粒渗透应用。