Ti-C-xFe体系自蔓延高温合成及机理

STUDY OF SELF－PROPAGATING HIGH－TEMPERAFURE SYNTHESIS OF Ti-C-Fe SYSTEM

采用自蔓延高温合成新技术合成ＴｉＣ／Ｆｅ复合材料，研究了原料组份、粒度对合成过程及产物特征的影响．探讨了燃烧反应及结构形成机理结果表明，随Ｆｅ含量的增大，燃烧合成温度降低，合成ＴｉＣ粒度变细，燃烧波速度在Ｆｅ含量为１０％（质量分数）时出现极大值．与碳黑作碳源对比，细粒石墨在反应合成过程中表现出更大的活性．用钢楔块燃烧波淬息法研究了合成过程，整个合成过程经历了金属的熔融、碳向熔融体中的溶解扩散、大团聚的形成、小的 ＴｉＣ。颗粒生长及ＴｉＣ长大等阶段。

TiC/Fe composites were synthesized by SHS method. The effects of Fe content, carbon sources and the size of Ti and C on the SHS processes of Ti-C-Fe, system and the structure characteristics of synthesized products were studied. The mechanisms of reaction process and structure forming process were discussed. It was shown that combustion temperature becomes lower and grain size of synthesized products becomes smaller with the increasing of Fe content and that combustion wave velocity reaches its highest as Fe content is 10%. Compared with carbon black, small graphite powder as carbon source has larger activity in reaction process. It was concluded by combustion front quenching method that the whole synthesis process includes melting of metal, diffusion of C into molten metal, the forming of agglomerates, formation and growth of TiC grains.