先驱体聚合物粘结法制备SiC纳米多孔陶瓷

Preparation of Nanoporous SiC Ceramics by Preceramic Polymer Bonding Method

采用SiC纳米粉体与聚碳硅烷(PCS)为原料低压成型低温烧结制备SiC纳米多孔陶瓷,研究了PCS含量对烧成纳米多孔陶瓷性能的影响。SEM和AFM微观形貌分析表明,PCS裂解产物将SiC纳米颗粒粘结起来,烧成陶瓷内部有大量的纳米孔存在。烧成SiC纳米多孔陶瓷孔径分布呈单峰分布、孔径分布范围窄,随着PCS含量的增大烧成多孔陶瓷强度增大,但孔隙率降低、烧结过程中坯体尺寸线收缩率增大。PCS含量为20wt%时三点弯折强度为36.8MPa,孔隙率为39.5%,平均孔径为49.3 nm。

SiC nanopowders and polycarbosilane（PCS） were mixed, molded at low pressure and then sintered at low temperature to obtain nanoporous SiC ceramics. Effect of PCS content on properties of nanoporous ceramics was studied. Micrographs of SEM and AFM show that the SiC nanopartieles are bonded by PCS pyrolysis products, and there are many nanopores in the nanoporous SiC ceramics. The pore size distribution of nanoporous SiC ceramics takes on a unimodal and narrow distribution. With the increase of the PCS content the flexural strength of the porous SiC ceramics increases, but the porosity decreases and the shrinkage of bodies during the sintering process increases. When PCS content is 20wt%, the flexural strength, porosity and average pore diameter of nanoporous SiC ceramic are 36.8 MPa, 39.5% and 49.3nm respectively.