摘要
以Mo粉和Si粉为原料,采用热压反应烧结法原位合成了Mo-Si系化合物及其复合材料,利用扫描电镜、X射线衍射仪等技术对材料的相结构和力学性能进行了初步的研究.结果表明:随原料粉中Mo含量的增加,生成物依次向MoSi2→Mo5Si3→Mo3Si变化;材料的硬度和弹性模量主要受气孔率的控制,具有极其弥散组织的Mo5Si3-MoSi2材料的硬度高达12 88GPa;Mo-Si系材料均为脆性断裂,弯曲强度和断裂韧性随Mo含量变化的趋势相同,其中MoSi2-Mo5Si3原位复合材料具有较好的综合力学性能.
Mo-Si compound composites were in situ fabricated by means of reactive hotpressing using Mo and Si powder as raw materials. Their phase composition and mechanical properties were investigated for design and fabrication of Mo-Si functionally graded material with hightemperature antioxidation properties in future. The results indicate that the reaction products in Mo-Si system vary in the order of MoSi2→Mo5Si3→Mo3Si with increasing content of Mo in the mixed powders. The hardness and the elastic modulus of insitu synthetic Mo-Si compound composites are mainly controlled by their porosity. The maximum hardness reaches to 1288 GPa in the Mo5Si3-MoSi2composites with very fine dispersive microstructure. The Mo-Si compound composites show macrobrittleness and the same varying tendency in flexural strength and fracture toughness with the change of Mo content. In Mo-Si compound composites, MoSi2-Mo5Si3 composite exhibits good combined mechanical properties.
出处
《材料科学与工艺》
EI
CAS
CSCD
2003年第3期248-250,253,共4页
Materials Science and Technology
基金
哈尔滨工业大学校青年基金资助项目(HIT.2001.18).
