原位反应合成Mo-Si化合物系复合材料

Mo-Si Compound Composites Synthesized by In Situ Reaction

采用反应烧结法原位合成了Mo-Si系化合物复合材料,利用X射线衍射仪、扫描电镜和电子探针等考察了材料的显微结构和相组成.结果表明,随原料粉中Mo含量的增加,Mo-Si系反应生成物依次向MoSi2→Mo5Si3→Mo3Si变化;各相分布较为均匀,组织致密,晶粒细小.

Mo-Si compound composites were synthesized by in situ reaction hot pressing. Their microstructure and phase composition were analyzed by means of scanning electron microscope (SEM), electron probe microanalyzer (EPMA) and X-ray diffractometer (XRD). The results indicate that the reaction products in Mo-Si system vary according to the order MoSi2-->Mo5Si3-->Mo3Si with increasing content of Mo in mixed powders. The sintered materials are nearly fully densified except the Mo3Si-Mo composite, exhibiting fine and homogeneous microstructures. Both MoSi2-Si and MoSi2-Mo5Si3 materials have an equivalent volume fraction and display an 'infiltration-flow structure'. In Mo3Si-Mo composite, the excess Mo phase exists in 'island-structure'.