Oxidation behaviors and mechanisms of Yb2SiO5-Yb2O3-Si-SiC ceramic fabricated by tape casting and reactive melt infiltration

The phase transition of thermally grown oxide (TGO) has been proven to be an important factor affecting the durability of EBCs. Yb2O3 and Yb2SiO5 can react with silica to form silicate, which can reduce the TGO thickness and extend the lifetime of EBCs. In this paper, the Yb2SiO5-Yb2O3-Si-SiC ceramic was prepared by tape casting combined with silicon reactive melt infiltration. The oxidation properties of the ceramic were evaluated at 1200-1400 degrees C. With the increase in temperature, the content of SiO2 in the oxide layer decreased and the content of Yb2Si2O7 increased. A dense and continuous Yb2Si2O7layer was formed at 1400 degrees C. Yb2Si2O7 is formed at the edge of Yb2SiO5, then Yb3+ diffuses outwards, Si4+ diffuses inwards and gradually forms Yb2Si2O7 from the outside to the inside.

Automated summary

The phase transition of thermally grown oxide (TGO) has been proven to be an important factor affecting the durability of EBCs. Yb2O3 and Yb2SiO5 can react with silica to form silicate, which can reduce the TGO thickness and extend the lifetime of EBCs.