| 摘要 |
PURPOSE: A method for improving the tensile of surface modified SiC sintered body is provided, to improve the abrasion-resistance and the breaking tensile. CONSTITUTION: A method comprises the steps of preparing a source powder A which is obtained by mixing beta-SiC, alumina (Al2O3) and yttria (Y2O3); preparing a source powder B which is obtained by mixing beta-SiC, alumina, yttria and 0.5-3 wt% of alpha-SiC which promotes the growth of particles; preparing the molded body whose surface part is made up of the source powder A and whose inner part is made up of the source powder B; and burying the molded body in the powder bed which contains BN and inhibits the growth of particles at the surface, and sintering it at the temperature of 1950-2050°C for 3-6 hours with Ar streaming. Preferably the source powder A comprises 85 wt% of beta-SiC whose size is less than 1 micrometer, 9 wt% of alumina (Al2O3) and 6 wt% of yttria (Y2O3), the source powder B comprises 82-84.5 wt% of beta-SiC whose size is less than 1 micrometer, 9 wt% of alumina, 6 wt% of yttria and 0.5-3 wt% of alpha-SiC, and the powder bed comprises 60 wt% of BN, 34 wt% of beta-SiC, 3.6 wt% of alumina and 2.4 wt% of yttria.
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