Papers by Keyword: Gadolinia

Abstract: The compressive stress-strain relation (room temperature) of SiC compact (75 vol% 800 nm SiC- 25 vol% 30 nm SiC) hot-pressed with 1.6 vol% Al2O3- 0.83 vol% Gd2O3 at 1950 °C was examined at a crosshead speed of 0.05 mm/min. The dense SiC (97.8 ± 1.5 % theoretical density) possessed 796 MPa of average flexural strength, 5.27 MPa・m1/2 of fracture toughness, 8.1 of Weibull modulus, and 475 GPa of average flexural Young’s modulus. The strains of SiC compacts along directions of height and width changed nonlinearly with applied compressive stress. The apparent Young’s modulus and Poisson’s ratio decreased with increasing strain along the direction of height and reached constant values of 275 ± 59 GPa and 0.214 ± 0.05, respectively. The steady-state compressive Young’s modulus was independent of the flexural strength.

Abstract: Oxygen self-diffusion and oxygen surface exchange investigations in the yttria-stabilized zirconia (3 and 8 mol% of Y2O3) and in the gadolinia-doped ceria (10 and 20 mol% of Gd2O3) ceramics in the temperature range from 250 to 450°C were performed by means of the 18O isotopic labeling and the SIMS profiling methods. The activation energies of these processes were determined. The results were discussed in comparison with the literature data extrapolated from higher temperatures.