自生长SiC晶须补强Al_2O_3复合材料

SELF-FORMED SiC WHISKER REINFORCED Al2O3 COMPOSITES

本文研究了制备SiC晶须补强Al_2O_3复合材料的一种新方法。该方法不需要外加晶须。将Al_2O_3、SiO_2与碳黑的混合粉末在Ar气氛中,1600℃反应2h,便可在Al_2O_3基体原料中合成均匀分布的SiC晶须。经1850℃热压后所制备的Al_2O_3-SiC_(w)复合材料的力学性能为:K-(1c)=5.6 MPa·m^(1/2)σb=530 MPa。通过X—射线衍射,扫描电镜等分析了复合材料的相组成及显微组织,并讨论了晶须的增韧机理。

A new process of preparing SiC whisker/Al2O3 matrix composites has been studied, in which there needs no additional whiskers. By mixing A12O3, SiO2 and carbon black, then reacting at 1600℃ for 2h under Ar armosphere, the homogeneous raw material compounded by A12O3 powders and SiC whiskers was produced. The composites, hot-pressed at 1850℃, exhibited high mechanical properties:KIC=5.6 MPa.m1/2,ob=530 MPa. Phase composition and microstructures of the composites were examined by XRD and SEM. The toughening mechanism of whiskers has been discussed.