摘要
通过机械合金化 冷等静压 高温烧结工艺制备了MoSi2 和稀土 /MoSi2 两种材料 ,测定了它们的室温抗弯强度、断裂韧性和导电性。结果表明 :稀土比SiC对MoSi2 具有更好的强韧化综合作用 ;加入 0 .9%稀土后 ,稀土 /MoSi2 材料比MoSi2 基体的弯曲强度提高了 46 %至 419 41MPa、断裂韧性提高了 81%达 5 .81MPa·m 1 /2 ;其强化机制为细晶强化和弥散强化 ,韧化机制为细晶韧化、裂纹的偏转和弯曲韧化。且稀土比SiC晶须对MoSi2 材料的导电性影响程度小得多 ,0 .9%稀土的加入仅使MoSi2 材料的电阻率增高了约 13.9%。
MoSi 2 and rare earth/MoSi 2 materials were prepared by mechanical alloying, IP and high temperature sintering techniques. Their room temperature properties such as bending strength, fracture toughness and electric conductivity were measured. The results show that rare earth has better strengthening and toughening effects on the MoSi 2 matrix than SiC. The bending strength and fracture toughness of 0.9% rare earth/MoSi 2 material are 419.41 MPa and 5.81 MPa·m 1/2 , respectively, which are increased by 46% and 81% than those of the matrix. The strengthening mechanisms of rare earth/MoSi 2 are fine grain and dispersion strengthening. The toughening mechanisms are fine grain toughening, crack deflection and bowing toughening. Moreover, the effect of rare earth on the electric conductivity of MoSi 2 is much weaker than that of SiC. The resistivity of matrix is only raised about 13.9% by addition of 0.9% rare earth.
出处
《中国稀土学报》
CAS
CSCD
北大核心
2001年第5期422-425,共4页
Journal of the Chinese Society of Rare Earths
基金
湖南省教委资助项目 ( 98C0 5 4)
