聚碳硅烷低温制备碳化硅泡沫陶瓷

Silicon Carbide Foamed Ceramics Prepared with Polycarbosilane at Low Sintering Temperature

采用具有连通气孔的聚氨酯海绵浸渍聚碳硅烷(polycarbosilane,PCS)、碳化硅微粉与四氢呋喃配制的浆料,挂浆素坯经热氧化不熔化处理后,在惰性气氛中于1 000℃热解制备碳化硅泡沫陶瓷。研究了固相含量和PCS含量对碳化硅泡沫陶瓷微观结构、体积密度、线收缩率和抗弯强度的影响,结果表明:固相含量为43.1%～69.6%、PCS含量为5%～20%的浆料在烧成过程中均可得到SiC泡沫陶瓷。随PCS含量提高,泡沫陶瓷线收缩率逐渐升高;抗弯强度随固相含量的提高而增加,随PCS含量的增加先升高再降低;固相含量为69.6%、PCS含量为10%的浆料制备的SiC泡沫陶瓷抗弯强度达3.9 MPa。

Polyurethane sponges were dipped into a slurry prepared with polycarbosilane（PCS）,silicon carbide powder and tetrahy-drofuran in order to obtain the green body.Silicon carbide foamed ceramics were fabricated of pyrolysis of the thermal oxidation treated green body at 1 000 ℃ under inert atmosphere.Effect of the solid content of slurry and PCS content on microstructure,vol-ume density,linear shrinkage and flexural strength of the foamed ceramics were investigated.The results show that silicon carbide foamed ceramics can be obtained from the slurry with the solid content of slurry from 43.1% to 69.6% and PCS content from 5% to 20%.The linear shrinkage gradually increased with increasing the PCS content.The flexural strength of the foamed ceramics in-creased with the increase of the solid content in slurry,but it increased firstly and then decreased with the increase of the PCS content.The flexural strength of the silicon carbide foamed ceramics prepared from slurry of the solid content of 69.6% and PCS content of 10% reached 3.9 MPa