High-temperature strength and oxidation behavior of Sc3+/Lu3+ co-doped α-sialon

The high-temperature strength and oxidation behavior of hot-pressed ScLu-α-sialon were investigated. The flexural strength at 1400 °C could reach 611 MPa, which was ∼94% of the room-temperature strength. A thin, dense oxidation scale was formed after exposure to air at 1300 °C. It exhibits parabolic oxidation behavior, with a maximum specific weight gain of 0.686 mg cm−2 and a rate constant of 4.21 × 10−6 mg2 cm−4 s−1 at 1300 °C. The excellent performance is attributed to the elimination of amorphous grain-boundary phase and formation of refractory secondary phases.