MoSi_2-WSi_2复合体系的自蔓延燃烧合成

Self-Propagating High-Temperature Combustion Synthesis of MoSi_2-WSi_2 Composite

摘要:

利用自蔓延燃烧合成法制备了 Mo Si2 - WSi2 复合粉体 ,并对合成产物进行了 X射线衍射分析。研究表明 ,通过自蔓延燃烧合成反应既可实现 Mo Si2 与 WSi2 的复合 ,又可通过调整反应物 Mo,W,Si的比例 ,在 Mo Si2 中引入 WSi2的同时还能引入足够量的 Mo5 Si3- W5 Si3相。W量的增加使体系的绝热温度降低 ,对自蔓延燃烧合成反应产生影响。研究还表明 Mo Si2 - WSi2 和 Mo5 Si3- W5 Si3均以固溶体的形式存在。

关键词:自蔓延燃烧合成,MoSi_2-WSi_2,复合,绝热温度,Mo_5Si_3-W_5Si

Abstract:

MoSi 2 WSi 2 powders have been synthesized by means of self propagating high temperature combustion. It was found that not only MoSi 2 WSi 2 but also Mo 5Si 3 W 5Si 3 can be synthesized by this method when suitable ratios of Mo, W and Si powders were used. As the W content increases, the adiabatic temperature of reactive system decreases, which influences the synthesis process. It is also confirmed that MoSi 2 WSi 2 and Mo 5Si 3 W 5Si 3 exist as solid solutions of [Mo (1-x) ,W x]Si 2 and [Mo (1-y) ,W y] 5Si 3, respectively.

Key words:self propagating high temperature combustion synthesis, MoSi_2 WSi_2, composite, adiabatic temperature, Mo_5Si_3 W_5Si_3