MoSi_2-SiC原位复合材料的制备及其性能研究

STUDY ON THE FABRICATION AND MECHANICAL PROPERTIES OF MoSi_2-SiC COMPOSITES IN-SITUATION

本文以Mo2C和S i粉为原料,利用真空热压烧结,研究了原位S iC颗粒增强MoS i2基复合材料的制备及其性能,结果表明:Mo2C∶S i∶MoS i2按质量百分比10.14∶6.98∶1配料,经1500℃×1 h真空热压烧结,可原位合成高强韧性的MoS i2-11%S iC复合材料,其密度为5.33g/cm3,显微硬度为16.9 GPa,断裂韧性K IC为8.1 MPam1/2,抗弯强度为452MPa。K IC和σb比纯MoS i2材料分别提高131.4%和64%。此外,对复合材料的室温增韧机理进行了初步探讨。

Employing vacuum hot press sintering and powder of Mo2C and Si, mechanical properties and fabrication of SiC particle reinforced MoSi2 matrix composites in-situation have been studied. The experimental results show that with weight percentage ratio of Mo2C：Si：MoSi2=10.14：6.98：1, MoSi2-11% SiC composites in-situation with high fracture toughness and strength has been fabricated at 1500℃ for 60 minutes by vacuum hot press sintering sucessfully. Density of this kind material is 5.33g/cm^3, microhardness is 16.9 GPa, fracture toughness is 8.1 MPam^1/2 and bending yield strength is 452 MPa. Compared with unreinforced MoSi2, the fracture toughness of MoSi2-11% SiC composites is increased by 131.4% and the bending yield strength by 64%. At the same time, the strengthening mechanism at room temperature of MoSi2-SiC composites has been investigated and discussed preliminarily.