热压Si_3N_4/MoSi_2复合材料的强韧化效果与机制  

Toughening Effect and Mechanism of Thermo-compressed Composite Si_3N_4/MoSi_2

作　　者：周宏明[1] 易丹青[1] 

机构地区：[1]中南大学材料科学与工程学院

出　　处：《机械工程材料》2008年第3期23-25,28,共4页Materials For Mechanical Engineering

基　　金：中国博士后基金资助项目(20060400261)

摘　　要：通过显微组织观察和力学性能测试,对亚微米Si3N4颗粒强韧化MoSi2的效果及其作用机制进行了初步研究和探讨。结果表明:复合材料中的Si3N4颗粒在基体的间层作用,可抑制MoSi2晶粒长大;断口呈现晶粒细小、裂纹扩展曲折和沿晶与穿晶混合型断裂等特征;Si3N4颗粒通过弥散强化和细化晶粒使复合材料强度提高,室温断裂韧度达到8.2 MPa.m1/2,通过晶粒细化、裂纹偏转和分支、微裂纹形成等机制的综合作用使复合材料增韧。Sub-micron Si3N4 particles reinforced MoSi2 matrix composites prepared by hot pressing had been studied.Through observation of the microstructure of MoSi2-based composite and the measurement of bending strength,micro-hardness and fracture toughness,the strengthening-toughening mechanism of this material was revealed.It is shown that the strengthening mechanism of the composites is the effect of dispersion strengthening and grain refining,and the toughening mechanism is a synthetic effect in terms of grain r...

关 键 词：MOSI2复合材料 SI3N4 力学性能 强韧化机制 

分 类 号：TG376.2[金属学及工艺—金属压力加工]