活性填料钨在聚碳硅烷转化陶瓷中的应用

Application of Tungsten in Polycarbosilane Derived Ceramics

研究了活性填料钨（Ｗ）在聚碳硅烷（ＰＣＳ）先驱体转化陶瓷中的应用。研究表明，Ｗ能有效降低陶瓷素坯的气孔率。Ｗ可与ＰＣＳ气态裂解产物、游离碳和Ｎ_２气氛反应生成新的化合物，提高ＰＣＳ的陶瓷产率。Ｗ还能提高烧成体的强度。当■（Ｗ）＝１５％时，烧成体的三点弯曲强度为 １０１ ＭＰａ，为不含活性填料的陶瓷烧成体的１．５倍。但是在先驱体中引入Ｗ不能抑制坯体在裂解过程中的收缩。Ｗ含量越高，陶瓷烧成体的线收缩越大。

The application of tungsten (W)in polycarbosilane (PCS)derived ceramics was investigated. The results showed that W could decrease efficiently the porosity of the green compact. W could react with gas volatile of PCS during pyrolysis, free carbon and N, to produce new compounds,which increased ceramic yield of PCS. W enhanced the three-point bending strength of the resulted ceramic with a strength of 101 MPa when the volume ration of 9(W) was 15 %,which was 1. 5 times of that of where W was excluded. However,W couldn't restrain the linear shrinkage of the green compact during pyrolysis. The linear shrinkage was higher with increasing the volume ration of (W).