SiC引入方式对反应熔渗原位纳米SiC/MoSi_2复合材料组织性能的影响

Effects of introduction methods of SiC on structure and property of in-situ nano SiC/MoSi_2 composites prepared by reactive melt infiltration

探讨了SiC引入方式对反应熔渗原位20wt%纳米SiC/MoSi_2复合材料TEM组织及力学性能的影响。结果表明:完全原位反应熔渗硅可获得基体相和增强相均为纳米尺度的SiC/MoSi_2复合材料,其组织中存在大量晶内层错等缺陷,可能会使纳米SiC/MoSi_2复合材料力学性能的提高不十分显著;而部分原位反应熔渗法中,SiC初始粉末的引入可缓解剧烈物相反应,所得纳米SiC/MoSi_2复合材料晶内缺陷消失,断口出现大量撕裂棱,复合材料力学性能大幅提高。

The effects of introduction methods of SiC on TEM structure and mechanical properties of 20wt% nano SiC/MoSi2 composites prepared by reactive melt infiltration were studied.The results show that,the nanometer scale of matrix phase and reinforced phase of SiC/MoSi2 composites can be obtained in the process of complete in-situ reactive infiltration silicon,but maybe due to the large number of fault defects inner crystals of the structure,the mechanical properties of the nano SiC/MoSi2 composites improve not too much;when preparing the composites in partial in-situ reactive melt infiltration method to relieve the severe phase reaction,the defects inner crystal in nano SiC/MoSi2 composites disappear,and there are a large number of tear ridges in the fracture,also,the mechanical properties of composites increase obviously due to the introduction of SiC initial powder.