耐食性に優れたアルミナセラミックス複合材料における微細構造と曲げ強度のばらつきとの関連性

概要

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The influences of ZrO_2 particle addition upon improvement in mechanical properties of Al_2O_3 ceramics and their degradation due to a deionized water environment under high temperature and high pressure were investigated in terms of the microstructural changes and residual strength characteristics. Sintered Al_2O_3 bodies containing, 3.3, 10.2, 21.7vol.% of 3mol% Y_2O_3-doped tetragonal ZrO_2 were made using a pressureless sintering process at 1550, 1600, 1650°C, respectively. These ceramic composites were corroded in deionized water jnder its equilibrium vapor pressure of 1.59MPa at 200°C. The effects of microstructure upon mechanical properties of Al_2O_3/ZrO_2 composites were studied for the speciemens treated with, and not treated with water under high temperature and pressure, by residual bending strength measurement, FE-SEM with EDX spectrometry observation and XRD and FE-TEM structural analysis. The mechanical properties were found to be superior when specimens were 21.7vol.% of ZrO_2 contents and sintered at 1550 °C. It was shown that the strength degradation due to the corrosion by deionized water molecule was suppressed in the case of the specimens with higher contents of ZrO_2 particles sintered at lower tempreatures. The correlation between bendin strength scatter and microstructural defects was discussed.
社団法人日本材料学会の論文
1999-03-15