Long-term ablation behavior of Al4SiC4-YB4 modified Cf/ZrB2-SiC composites at 2600 °C

Long-term ablation behavior of Al 4 SiC 4 -YB 4 modified C f /ZrB 2 -SiC composites was characterized by air plasma torch at 2600 °C for 300 s. The phase composition and the microstructure evolution of the composites were investigated. The addition of YB 4 promotes the formation of nano t- Zr 0.92 Y 0.08 O 1.96 crystals, decreasing the phase transition stress in the oxide layer and reducing the volatilization of the glassy phase . However, the addition of Al 4 SiC 4 reduces the melting point of Zr-based oxides and the viscosity of the oxide layer. Therefore, the air plasma torch blows the oxide layer away, leading to the increase of linear recession rate.