Refractory self-reinforced Y-α-SiAlON with barium aluminosilicate glass ceramic addition

Refractory Y-α-SiAlONs with elongated microstructure were obtained by hot pressing and post-heat treatment using BaAl2Si2O8 (BAS) as an additive. The results showed that BAS not only served as a liquid phase sintering aid to promote densification, but also facilitated the development of elongated α-sialon grains, resulting in excellent room and high-temperature mechanical properties. Increasing the amount of BAS addition and post-heat treatment could further effectively promote the anisotropic growth of α-SiAlON grains, the room-temperature flexural strength and fracture toughness of 10 wt% BAS/Y-α-SiAlON could reach 634 MPa and 7.2 MPa m1/2, respectively. The resultant materials could maintain the room strength up to 1400 °C due to the extensive crystallization of BAS.