A Weibull statistical analysis of the mechanical properties of SiC ceramics was carried out by immersion in acidic and alkaline solutions. The heat treatment was carried out at 1373 K. The corrosion of SiC was carried out in acidic and alkaline solutions under KSL1607. The bending strength of corroded crack-healed specimens decreased 47％ and 70％ compared to those of uncorroded specimens in acidic and alkaline solutions, respectively. The corrosion of SiC ceramics is faster in alkaline solution than in acid solution. The scale and shape parameters were evaluated for the as-received and corroded materials, respectively. The shape parameter of the as-received material corroded in acidic and alkaline solutions was significantly more apparent in the acidic solution. Further, the heat-treated material was large in acidic solution but small in alkaline solution. The shape parameters of the as-received and heat-treated materials were smaller in both acidic and alkaline solutions.
ZrO2 composite ceramics was measured the Vickers hardness, and Weibull statistical analysis was used to evaluate the reliability of the measured data. The specimens were heat-treated for 1, 5 and 10h at temperatures of 1073 K and 1173 K, and were corroded for 400 hours in acidic and alkaline solutions. The specimens were as follows: Yttria-stabilized ZrO2 monolithic ceramics, ZrO2/SiC composite ceramics with SiC added to improve crack healing ability and ZrO2/SiC/TiO2 composite ceramics with TiO2 added for the increase of strength. The 2-parameter Weibull probability distribution can be applied to the Vickers hardness. In the Weibull statistical analysis of the corroded ZrO2 composite ceramics, the shape parameters and scale parameters can be used to determine the dispersion and to predict the strength/hardness.
Al2O3 composite ceramics was measured the Vickers hardness of ceramics, and Weibull statistical analysis was used to evaluate the reliability of the measured data. The specimens were heat-treated for 0.5, 1 and 10h at temperatures of 1473 K, 1573 K and 1673 K, and were corroded for 400 hours in acidic and alkaline solutions. The specimens were made with different amounts of SiC. Namely, 10 wt.%, 15 wt.% and 20 wt.%. SiC was added to improve crack healing (heat treatment) ability. The 2-parameter Weibull probability distribution can be applied to the Vickers hardness. In the Weibull statistical analysis of the corroded Al2O3 composite ceramics, the shape parameters and scale parameters can be used to determine the dispersion and to predict the strength/hardness.