Effect of Y_2O_3 and Total Oxide Addition on Mechanical Properties of Pressureless Sintered β-SiC

摘要

The effect of Y2O3 and the total oxide volume fraction (Y2O3+Al2O3) on density and mechanical properties of lowtemperature (1770～1940℃) pressureless sintered β-SiC ceramics were presented. The optimum temperature forpressureless sintering of β-SiC was found to be ～1850℃ and the optimum content of Y2O3 in the oxides was foundto be between 40 and 57 wt pct. The highest sintered density was achieved by adding oxides at 14 vol. pct. Both ofthe highest strength and fracture toughness were achieved at ～14 vol. pct oxide addition and yttria concentrationsbetween 40 and 57 wt pct in the oxides. Hardness, on the other hand, was found to be the highest for samples with14 vol. pct oxide addition and ～64 wt pct Y2O3 in oxides.