短链两亲分子活性剂制备氮化硅泡沫陶瓷

采用直接起泡法制备氮化硅泡沫陶瓷,研究了长链表面活性剂与短链两亲分子活性剂对泡沫稳定性的影响,分析了Si3N4泡沫陶瓷的微观结构。结果表明：与长链表面活性剂稳定的泡沫相比,短链两亲分子稳定的泡沫稳定性较好,泡体呈现球形或椭球形。通过控制发泡工艺制备出气孔尺寸分布均匀的开孔和闭孔两种不同孔结构的多孔氮化硅泡沫陶瓷,闭孔氮化硅泡沫陶瓷的气孔率和抗弯强度分别为40%和106MPa;开孔氮化硅泡沫陶瓷的气孔率和抗弯强度分别为80%和28MPa。

Preparation of Si3N4 Foam Ceramics Using Short-Chain Amphiphile

Si3N4 foam ceramics were prepared by a direct foaming method. The influences of long-chain surfactants and short-chain amphiphiles on the stability of the bubbles were investigated, and the microstructure of the sintered Si3N4 foam ceramics was ana- lyzed. The results indicate that the bubbles produced by long-chain surfactants appear unstable. In contrast, the bubbles produced by short-chain amphiphiles were stable, and the bubbles were spherical or oval shape. Si3N4 foam ceramics with the open-pore and closed-pore structures were obtained by controlling the process parameter of foaming, and the pore size distribution of Si3N4 foam ceramics was uniform. The porosity and flexural strength of Si3N4 foam ceramics with the closed pore structure were 40% and 106 MPa, and those with the open pore structure were 80% and 28 MPa, respectively.