Effect of low activation rare-earth oxides on sintering of β-SiC

The feasibility of sintering β-SiC at 1850 ℃ with using low-activation rare-earth oxides as sintering additives was studied. Thermodynamic calculation suggested that all five rare-earth oxides (Y 2 O 3 , Sc 2 O 3 , CeO 2 , La 2 O 3 , and Pr 6 O 11 ) were suitable sintering additives. Comprehensive microstructure characterization further revealed that Pr 6 O 11 was the most effective sintering additive as it suffered the least influence from the content effect. A mechanism based on liquid phase sintering was proposed based on microstructure observations. The radiation stability of sintered SiC was investigated as well. The intergranular phases (rare-earth oxides and silicates) and SiC grains remained after being irradiated to 17 dpa at 750 ℃.